What is the next number of the following sequence 22, 43, 84, 165, 326, 647, ........

M4maths Previous Puzzles

05 May 2014 Sequence What is the next number of the following sequence 22, 43, 84, 165, 326, 647, ........: OPtion
1) 1188
2) 1287
3) 1286
4) 1288
5) 1387
6) 1289
7) 1388
8) 1389
9) 1282
10)None of these; Correct Option: 4 Best Solution (89)

Ann Theressa 10 years AGO

22
22*2 - 1 = 43
43*2 - 2 = 84
84*2 - 3 = 165
165*2 - 4 = 326
326*2 - 5 = 647
647*2 - 6 = 1288

Like? Yes (8) | No (2)

RAKESH 10 years AGO

22, 43, 84, 165, 326, 647, ...
2 2, 4 3, 8 4, 16 5, 32 6, 64 7, 128 8

1288

Like? Yes (6) | No (1)

Dr.Dipin Singh 10 years AGO

22*2-1=43
43*2-2=84
84*2-3= 165
165*2-4= 326
326*2-2-5= 647
647*2-6= 1288

Like? Yes (2) | No

Mahalakshmi 10 years AGO

22+21=43
43+41=84
84+81=165
165+161=326
326+321=647
647+641=1288
so ans is 4)1288

Like? Yes (2) | No (1)

Rajasekhar Reddy 10 years AGO

22+(22-1) = 43
43+(43-2) = 84
84+(84-3) = 165
.
.
. 647+(647-6) = 1288

Like? Yes (2) | No (1)

upendra singh chahar 10 years AGO

add 1 in unit digit;
and double remaining digits, as
2*2 = 4; 2+1 = 3 => 43
same
(64*2) = 128; 7+1 = 8 => 1288

Like? Yes (2) | No (1)

RAVI GUPTA 10 years AGO

22*1=22
22*2=44-1=43
43*2=86-2=84
84*2=168-3=165
165*2=330-4=326
326*2=652-5=647
647*2=1294-6=1288

Like? Yes (1) | No

SREEVIDHYA P P 10 years AGO

First number 22
Then (2*2)(2+1)=43
(4*2)(3+1)=84.......
last (64*2)(7+1)=1288

ie.,first no.

Like? Yes (1) | No

Vivek Tiwari 10 years AGO

the second number is two times the first number -1, the third no is two times the second no -2 and so on, hence the last number would be two times 647-6 i.e 647*2-6=1288

Like? Yes (1) | No

chandan jha 10 years AGO

22*2=44-1=43
43*2=86-2=84
...647*2=1294-6=1288.

Like? Yes (1) | No

garima singh 10 years AGO

the sequence has the last bit in increasing order and the starting bits are exactly double of the previous number's starting bit.

Like? Yes (1) | No

vivek poddar 10 years AGO

multiply by 2 and minus by 6

Like? Yes (1) | No

Rahur Kumar Sinha 10 years AGO

Each number multiplied by to and then subtracted 1,2,3,4,5,6... sequently to get the next consecutive number

Like? Yes (1) | No

Ranjitha 10 years AGO

Add the two digits of previous number which is the first digit of next number and the second digit is obtained by incrementing second digit of previous number.

Like? Yes (1) | No

indrajeet yadav 10 years AGO

22*2=44-1=43
43*2=86-2=84
84*2=168-3=165
165*2=330-4=326
326*2=652-5=647
647*2=1294-6=1288

Like? Yes (1) | No

manish chauhan 10 years AGO

647*2-6=1288

Like? Yes (1) | No

AMIT SINGH 10 years AGO

as 43=22*2-1
84=43*2-2
165=84*2-3
similarly
647*2-6=1288

Like? Yes (1) | No

llamar 10 years AGO

22+21=43
43+41=84
84+81=165
165+161=326
326+321=647
647+641=1288

Like? Yes (1) | No

Udhaya kumar 10 years AGO

2 4 8 16 32 64 128
2 3 4 5 6 7 8
1288........

Like? Yes (2) | No (1)

ankita jain 10 years AGO

the firt digits are like 2, 2 square....64*2=128
next second digits are like=2,3,4,5,6,7,8
so ans-1288

Like? Yes (1) | No

srilakshmi 10 years AGO

22 --> (2*2)(2+1) = 43
43 ---> (4*2)(3+1) = 84
84 ----> (8*2)(4+1) = 165
.
.
.
.
647 ----> (64*2)(7+1) = 1288

Like? Yes (1) | No (1)

Devendra Marghade 10 years AGO

22*2-1= 44-1 =43
43*2-2= 86-2 =84
84*2-3=168-3 =165
165*2-4=330-4=326
326*2-5=652-5=647
647*2-6=1294-6=1288

Like? Yes (1) | No (1)

MD SOHAIL AKHTER 10 years AGO

22*2-1=43
43*2-2=84
84*2-3=165
165*2-4=326
326*2-5=647
647*2-6=1288

so the correct option is (4)

Like? Yes (1) | No (1)

ASHISH MITTAL 10 years AGO

22+21=43
43+41=84
84+81=165
165+161=326
326+321=647
647+641=1288
so answer will be option (4)

Like? Yes (1) | No (1)

Sagar Jinachandran 10 years AGO

43-22= 21
84-43= 41
165-84= 81
326-165= 161
647-326= 321
the next difference is 641
so next number = 647+641=1288
Option 4

Like? Yes (1) | No (1)

ravi prakash 10 years AGO

Multiply The digit except unit digit with 2 and increment by 1 to unit place digit and write the no.
64*2=128
and
7+1=8 in unit place
1288 is the answer

Like? Yes (1) | No (1)

susmit 10 years AGO

22*2-1=43
43*2-2=86 and so on
so
647*2=6= 1288

Like? Yes (1) | No (1)

harshal agrawal 10 years AGO

22*2 - 1 = 43
43*2 - 2 = 84
84*2 - 3 = 165
165*2 - 4 = 326
326*2 - 5 = 647
647*2 - 6 = 1288

Like? Yes (1) | No (1)

SIBNATH HALDER 10 years AGO

22*2-1=43
43*2-2=84
84*2-3=165
165*2-4=326
326*2-5=647
647*2-6=1288

Like? Yes (1) | No (1)

pravallika pasam 10 years AGO

Double the number and reduce 1,2,3,4,5,6
22+22-1=43
43+43-2=84
.
.
.
647+647-6=1288

Like? Yes (1) | No (1)

Leelanand Kumar Yalla 10 years AGO

647*2-6=1288;

Like? Yes (1) | No (1)

vicky kumar 10 years AGO

22*2-1=43
43*2-2=84
84*2-3=165
165*2-4=326
326*2-5=647
647*2-6=1288

Like? Yes (1) | No (1)

S Prakash 10 years AGO

Take Difference in first 2 numbers,then subtract -1 and multiply by 2 and add +1.Then add this new value and previous value.

43-22=21
(21-1)*2+1=41
43+41=84
(41-1)*2+1=81
84+81=165
(81-1)*2+1=161
165+161=326
(161-1)*2+1=321
326+321=647
(321-1)*2+1=641
647+641=1288
Answer is 1288.
Option 4.

Like? Yes (1) | No (1)

Keshav Kishlay 10 years AGO

64*2=128
7+1=8
so, 1288

Like? Yes (1) | No (1)

Yekollu Muneeswar 10 years AGO

ans 1288
22 * 2 = 44 -1 =43
43 * 2 = 86 -2 =84
84 * 2 = 168 -3 =165
165 * 2 = 330 -4 =326
326 * 2 = 652 -5 =647
647 * 2 = 1294 -6 =1288

Like? Yes (1) | No (1)

gowtham 10 years AGO

IN GIVEN SERIES
first digit is power of 2^(n+1) for n=0,1,2,3...
where as second digie is order ie.,2 3 4
2=2
2^2=4
2^3=8
2^4=16
2^5=32
2^6=64
2^7=128
where as second 2,3,4,....
compare with giwen serise
22,43,84,165,326,647,is the next serise number 1288

Like? Yes (1) | No (1)

Ramesh.V 10 years AGO

The reason for MULTIPLY TO THE FIRST DIGIT
EG:-2*2=4,4*2=8,8*2=16,16*2=32,32*2=64,(64*2=128).
so the sequence will be start for 128 next the lost digit will find out for digits 2,3,4,5,6,7,( 8 ).
THAT'S WILL BE THE ANSWER[1288].

Like? Yes (1) | No (1)

T.Aravinth kumar 10 years AGO

647+ 641=1288

Like? Yes (1) | No (1)

Sudipta Mukherjee 10 years AGO

647*2=1294-6=1288

Like? Yes (1) | No (1)

ABHOY KUMAR 10 years AGO

22
43=22*2-1
84=43*2-2
165=84*2-3
326=165*2-4
647=326*2-5
NEXT=647*2-6=1288

Like? Yes (1) | No (1)

MONIKA 10 years AGO

22
22+21=43
43+41=84
84+81=165
165+161=326
326+321=647
647+641=1288

Like? Yes (1) | No (1)

KALIA MUDULI 10 years AGO

Given Sequence are 22, 43, 84, 165, 326, 647, .....

22*2-1 = 44-1=43
43*2-2 = 86-2= 84
84*2-3 = 168-3= 165
165*2-4 = 330-4= 326
326*2-5 = 652-5= 647
647*2-6 = 1294-6= 1288

so Ans- Op(4)

Like? Yes (1) | No (1)

arijit roy 10 years AGO

each gap between 2 consequtve number increases like
(2 * before gap value) - 1

Like? Yes (1) | No (1)

RAJESHKUMAR 10 years AGO

22*2-1= 43
43*2-2= 86
86*2-3= 165
165*2-4=326
326*2-5=647
647*2-6=1288

Like? Yes (1) | No (1)

sruthi 10 years AGO

22,43,84,165,326,647,
here take
22 =2+2 =4 and 2+1=3 so next number 43
43=4+4=8 and 3+1=4 so next number is 84
84=8+8=16 and 4+1=5 so next number is 165
165=16+16=32 and 5+1=6 so next number is 326
326=32+32=64 and 6+1=7 so next number is 647
647=64+64=128 and 7+1=8 so next number is 1288
option 4 is answrer

Like? Yes (1) | No (1)

SHUBHAM KUMAR 10 years AGO

647*2-6

Like? Yes (1) | No (1)

g.soujanya 10 years AGO

22+22=44-1=43
43+43=86-2=84
84+84=168-3=165
165+165=330-4=326
326+326=652-5=647
647+647=1294-6=1288

Like? Yes (1) | No (1)

steffy edmond 10 years AGO

Ans:Option 4) 1288
The given sequence is 22, 43, 84, 165, 326, 647, ........
The last digit in each number is in the increasing order 2,3,4,5,6,7.... so the next number will be 8.
the first digits in each number2,4,8,16,32,64etc are multiplied by 2to get the next=2,4,8,16,32,64,....so the next number is 64*2=128
so the ans is 1288

Like? Yes (1) | No (1)

Hemalatha 10 years AGO

64*2=128 and adding 8

Like? Yes (1) | No (1)

salma 10 years AGO

22+20+1=43
43+40+1=84
84+80+1=165
165+160+1=326
326+320+1=647
647+640+1=1288

Like? Yes (1) | No (1)

Mukesh Nayal 10 years AGO

second number is twice plus 1 of first number

Like? Yes (1) | No (1)

Purosotam Gupta 10 years AGO

by the question
22*2=44-1=43
43*2=86-2=84
84*2=168-3=165
.
.
.
same as
647*2=1294-6=1288

Like? Yes (1) | No (1)

NIRUPOM GHOSH 10 years AGO

Prev no are 22,43,84,165,326.Differences of difference is increasing double.Next no. is 647+641=1288.

Like? Yes (1) | No (1)

gaurav bhatt 10 years AGO

22= 2*2=4 and 2+1=3 so next digit = 43
same as
647= 64*2=128 and 7+1=8 so next digit= 1288
Answer: option 4

Like? Yes (1) | No (1)

DINESH KUMAR 10 years AGO

22*2-1=43
43*2-2=84
84*2-3=165
165*2-4=326
326*2-5=647
647*2-6=1288

Like? Yes (1) | No (1)

subramani 10 years AGO

22
(22*2)-1=43
(43*2)-2=84
(84*2)-3=165
(165*2)-4=326
(326*2)-5=647
(647*2)-6=1288
so ans is 1288 and option is 4

Like? Yes (1) | No (1)

SOUVIK TALUKDAR 10 years AGO

because 647:
(64*2)(7+1)
=(128)(8)
=1288

Like? Yes (1) | No (1)

S.SHAFI 10 years AGO

First digit in the number is double of previous number's first digit..
Second digit in the number is increased by 1 to the previous number's second digit....

Like? Yes (1) | No (1)

Sundar Kumar 10 years AGO

22,22+21,43+41,84+81,165+161,326+321,647+641...
answer = 4) 1288

Like? Yes (1) | No (1)

Komala.G 10 years AGO

Option (4)
22*2 = 44-1 = 43
43*2 = 86-2 = 84
84*2 = 168-3 = 165
165*2 = 330-4 = 326
326*2 = 652-5 = 647
647*2 = 1294-6 = 1288

Like? Yes (1) | No (1)

Sriparna Boote 10 years AGO

Here 2*2=4 and 2+1=3 so 2nd no is 43
similarly, 4*2=8 and 3+1=4 3rd no is 84
in this way 64*2=128 and 7+1=8 so the no is 1288

Like? Yes (1) | No (1)

adarsh yadav 10 years AGO

22+21=43,44+41=84,84+81=165,165+161=326,326+321=647,647+641=1288, hence the answer is 1288

Like? Yes (1) | No (1)

Govind raj 10 years AGO

22*2=44-1=43
43*2=86-2=84
84*2=168-3=165
165*2=330-4=326
326*2=652-5=647
647*2=1294-6=1288....

Like? Yes (1) | No (1)

vasu kumari 10 years AGO

22*2-1=43,43*2-2=84.........647*2-6=1288

Like? Yes (1) | No (1)

SAMRIDHI 10 years AGO

IF WE Check last digit of the sequence so it is forming a series 2,3,4,5,6,7, so next answer will be the one who have 8 in its last digit then the previous digit are the double of the one before 2*2=4
4*2=8
8*2=16
16*2=32
32*2=64
64*2=128
so answer will be 1288

Like? Yes (1) | No (1)

Parveen Soni 10 years AGO

22*2-1=43
43*2-2=84
84*2-3=165
165*2-4=326
326*2-5=647
647*2-6=1288

Like? Yes (1) | No (1)

Satish Zod 10 years AGO

647 + (647 - 6) = 1288

Like? Yes (1) | No (1)

Ankush Kumar 10 years AGO

22*2-1=43
43*2-2=84
84*2-3=165
165*2-4=326
326*2-5=647
647*2-6=1288

Like? Yes (1) | No (1)

Chithra 10 years AGO

64*2=128
next last digit 8
1288

Like? Yes (1) | No (1)

Hari Sankhar 10 years AGO

add the number with same number and subtract each by 1,2,3,4,5,6etc.,

Like? Yes (1) | No (1)

sai keerthi mettu 10 years AGO

first digit is power of 2 followed by the next number of previous number

Like? Yes (1) | No (1)

yellapanthula pranav 10 years AGO

22 * 2 -1 =43
43 * 2 -2 =84
84 * 2 -3 =165
165 * 2 -4 =326
326 * 2 -5 =647
647 * 2 -6 =1288

Like? Yes (1) | No (1)

Nishdha Bhatt 10 years AGO

22* 2 = 44, 44-1=43
43* 2 = 86, 86-2=84
84* 2 = 168, 168-3=165,,,,, so,,,, going on like this we get 647*2=1294, 1294-6= 1288

Like? Yes (1) | No (1)

Clair Christ D 10 years AGO

22,22*2-1,43*2-2,84*2-3,165*2-4,326*2-5,647*2-6

Like? Yes (1) | No (1)

priya agarwal 10 years AGO

the difference b/w them is number divided by 10 + 1

Like? Yes (1) | No (1)

VIVEK VICTOR 10 years AGO

1st diff : 22-1=21
2nd diff: 43-2=41
...
...
Diff after 647 = 647-6 i.e. 641
so, no. Is 1288

Like? Yes (1) | No (1)

Sukanya 10 years AGO

22*2-1=43
43*2-2=84
84*2-3=165
165*2-4=326
326*2-5=647
Similarly 647*2-6=1288

Like? Yes (1) | No (1)

Rajesh Pattanaik 10 years AGO

(647*2)-6=1288

Like? Yes (1) | No (1)

AMIT 10 years AGO

22*2-1=43
43*2-2=84
84*2-3=165
165*2=4=326
326*2-5=647
647*2-6=1288

Like? Yes (1) | No (1)

Ajinkya Bhagat 10 years AGO

first digit is x*2 like 2*2=4 4*2=8...
second digit is like 2,3,4,5,6,7,8

Like? Yes (1) | No (1)

Varunraj Reddy 10 years AGO

22=>2 2=>2*2 2+1=>4 3=>43
43=>4 3=>4*2 3+1=>8 4=>84
84=>8 4=>8*2 4+1=>16 5=>165
165=>16 5=>16*2 5+1=>32 6=>326
326=>32 6=>32*2 6+1=>64 7=>647
647=>64 7=>64*2 7+1=>128 8=>1288 Ans

Like? Yes (1) | No (1)

Rahul Bhadana 10 years AGO

22
(2*2),(2+1)=43
(4*2),(3+1)=84
(8*2),(4+1)=165
(16*2),(5+1)=326
(32*2),(6+1)=647
so finally
(64*2),(7+1)=1288

Like? Yes (1) | No (1)

DHANANJAY Kumar 10 years AGO

2 2
*2| |+1
4 3
*2| |+1
8 4
| |
16 5
| |
32 6
| |
64 7
*2| |+1
128 8 ----- ans: 1288
--------------

Like? Yes (1) | No (1)

Thrinadhsai 10 years AGO

first do the difference between to numbers
43-22=21
84-43=41
165-84=81
here units place doesn't change but tens place changes in multiples of two
326-165=161
647-326=321
so ans is 1288
because 1288-647=641

Like? Yes (1) | No (1)

jagruti bhagwan salvi 10 years AGO

22+22=44=44-1=43
43+43=86=86-2=84
84+84=168=168-3=165
165+165=330=330-4=326
326+326=652=652-5=647
647+647=1294=1294-6=1288

Like? Yes (1) | No (1)

Pallab Das 10 years AGO

22*2-1=43
43*2-2=84
84*2-3=165
165*2-4=326
326*2-5=647
647*2-6=1288

Like? Yes (1) | No (1)

amit singh 10 years AGO

647*2-6=1288

Like? Yes (1) | No (1)

Gitanjali K 10 years AGO

22 + 22 = 44-1 = 43 is the next no.
43+43 = 86-2 = 84
84+84 = 168-3 = 165
165+165 = 330-4 = 326
326+326 = 652-5 = 647
647+647 = 1294-6 = 1288 is the answer

Like? Yes (1) | No (2)

SAMPATH KUMAR 10 years AGO

22,43,84,165,326,,647
(twice of the number)(sequence number)
(2)(2)
(4)(3)
(8)(4)
(16)(5)
(32)(6)
(64)(7)
so most probably the next number is
(128)(8)
and the answer is 1288

Like? Yes (1) | No (2)

Dimple

India

Punjab

Time: 00:01:33

Points

Maths Quotes

maths and life is same,because both contains lots of problems

saranya rajan

If I feel unhappy, I do mathematics to become happy. If I am happy, I do mathematics to keep happy.

Alfred Renyi

Placed User Comments

M4Math helped me a lot.

Vipul Chavan 4 years ago

Thanks m4 maths for helping to get placed in several companies.
I must recommend this website for placement preparations.

yash mittal 5 years ago

What is the next number of the following sequence 22, 43, 84, 165, 326, 647, ........

M4maths Previous Puzzles

05 May 2014 Sequence

What is the next number of the following sequence
22, 43, 84, 165, 326, 647, ........

OPtion

Sponsored Links

Challenger of the Day

Maths Quotes

Placed User Comments

Site Links

Useful Info

Placement papers