1, 5, 15, 34, 65, 111, ....... next number of the sequence will be

Vignesh   12 years AGO

Next number will be 175. So, answer None Of These(Option 10).

Series is formed by using formula
[n*(n^2 + 1)/2]. where N starts from 1.

Like? Yes (12) | No (7)  

Riya Adhikari   12 years AGO

take successive differences like 1,5,15,34,65,111
-- 4,10,19,31,46
----6, 9, 12,15

so next will be 18 sum it with upper term n finally u will get 64+111=175

Like? Yes (8) | No (3)  

dineshv   12 years AGO

1, 5, 15, 34, 65, 111,X
TAKE THE DIFF B/W TWO CONSEQUETIVE NUMBERS
4 10 19 31 46 X-111
AGAIN TAKE THE DIFF
6 9 12 15 18---> SHOULD BE OMING
THEREFORE X-111-46=18
X-157=18
X=175

Like? Yes (10) | No (6)  

Romoni   12 years AGO

sum of next n natural numbers.i.e
split the natural numbers in groups
1, 2 3, 4 5 6, 7 8 9 10
the sum of these groups forms the sequence

Like? Yes (3) | No   

Flower   12 years AGO

10. None of these
Answer :175

1, 5, 15, 34, 65, 111, 175, 260,

Explanation:

M = n(n^2 + 1)/2
n =1, 2, 3, 4, 5, 6, 7,8,

M=1,5, 15, 34, 65, 111, 175, 260,

Like? Yes (7) | No (5)  

srinivas s   12 years AGO

1 5 15 34 65 111 175
4 10 19 31 46 64
6 9 12 15 18
3 3 3 3

difference b/w two consecutive numbers is same at fourth level of subtraction.

Like? Yes (4) | No (3)  

kunal sharma   12 years AGO

it should be 175. 1+4=5, 5+10=15, 15+19=34, 34+31=65, 65+46=111, 111+64=175.

Like? Yes (3) | No (4)  

prithviraj sanningannavar   12 years AGO

1 5 15 34 65 111 175

4 10 19 31 46 64

6 9 12 15 18

3 3 3 3
answer is 175

Like? Yes (2) | No (4)  

J.P.Raja Suresh   12 years AGO

=> 1, 5, 15, 34, 65, 111, 175..
=> 4 10 19 31 46 64
=> 6 9 12 15 18
=> Ans : 175 (Option : 10)

Like? Yes (2) | No (4)  

J.P.Anitha   12 years AGO

=> 1, 5, 15, 34, 65, 111, 175..
=> 4 10 19 31 46 64
=> 6 9 12 15 18
=> Ans : 175 (Option : 10)

Like? Yes (2) | No (4)  

shyoram Gurjar   12 years AGO

1 5 15 34 65 111 175
+4 +10 +19 +31 +46 +64
+6 +9 +12 +15 +18

The formation of series is shown above It is series of diff and diff


ans 175 option 10 non of these

Like? Yes (3) | No (6)  

Balakumaran N.A   12 years AGO

1,5,15,34,65,111 => 4 , 10, 19, 31, 46.
Again take differences: 6, 9, 12,15, 18, ...
According to Differences in Sequence:
46 + 18 = 64 + 111 = 175 is the answer... Opt 10.

Like? Yes (1) | No (4)  

Niraj   12 years AGO

1 5 15 34 65 111 175
4 10 19 31 46 64 => Difference
6 9 12 15 18 => Difference

So option 10

Like? Yes (1) | No (4)  

Dr.Dipin Singh   12 years AGO

Tn = (n+n^3)/2

Here T7 = (7+343)/2 =350/2=175 .

so none of these ... option 10

Like? Yes (3) | No (6)  

Rakesh Kumar Kohli   12 years AGO

Ans. 175

Solution:
1 5 15 34 65 111 175.....
1 5 15 34 65 111.....
.............................
4 10 19 31 46 64.....
1 4 10 19 31 46.....
.............................
3 6 9 12 15 18.....
...............................
which is a series with common difference 3.
By moving backward we find the answer.

Like? Yes (2) | No (5)  

niru   12 years AGO

1,5,15,34,65,111
we write it as
4,10,19,31,46
further
6,9,12,15
so the ans is 18+46+111=175
this is not in the ans so ans is 10

Like? Yes (2) | No (5)  

sumit.kumar singh   12 years AGO

in this sequence formula n(n^2+1)/2 is applied for eg: if n=1 then 1(1^2+1)/2=1 for n=2 2(2^2+1)/2=5,for n=3 3(3^2+1)/2=15 like this we also get the required sequence 34,65,111,and next number wil be 7(7^2+1)/2=175 so option is (10)

Like? Yes (2) | No (5)  

Abinaya   12 years AGO

ans:175................
there is no option like this............. so none of this...............

Like? Yes (1) | No (4)  

Shilpa   12 years AGO

1, 5, 15, 34, 65, 111.....
+4 +10 +19 +31 +46 (gap between the no.)
+6 +9 +12 +15 so next no is +18
therefore 18+46 =64
next no is 111+64 =175

Like? Yes (1) | No (4)  

susmit   12 years AGO

formula is x(x^2+1)/2
1(1^2+1)/2=1
2(2^2+1)/2=5
3(3^2+1)/2=15
so 7(7^2+1)/2=175
so ans is option no. 10

Like? Yes (1) | No (5)  

A.P.Singh   12 years AGO

sequence is given by numbers satisfying

nth term = n*(n^2+1)/2
when n=1, term =1
For n=2, T2= 2*5/2=5
..
..
...
For n=7, T7 = 7*50/2= 175 which is none of these.

Like? Yes (3) | No (7)  

vignesh waran A   12 years AGO

given 1,5,15,34,65,111, ? As SeqI
difference seq.
4,10,19,31,46,? As seq II
again difference seq
3,6,9,12,15,? AS seq III
here ? Is 18
take it to the seq II
? IS 46+15=64
TAKE IT TO THE SEQ I
My ANS IS 111+64=175

Like? Yes (1) | No (5)  

Tijo Jose   12 years AGO

Answer is 175
The first level of differences gives the sequence 4, 10, 19, 31, 46, ...
The second level of differences gives the sequence 6, 9, 12, 15, ...
So, the next number is 18, which inturn gives the next number in the first level diff. as 64.
That will result in the next number of the sequence being 111+64 = 175

Like? Yes (2) | No (7)