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(#M40031242) IBM Numerical Ability question number series Keep an EYE

Q. What is the next number of the following sequence.
4,2,5,9,5,11,13,7,16,17,9,21,...

Asked In IBM (11 years ago)

Unsolved Read Solution (4)

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Read Solution (4) :

denise clarke  (11 years ago)

sequence goes -2, +3, +4, -4, +6, +2, -6, +9, +1, -8, +12
There are three diff patterns
(a) -2, -4, -6, -8
(b) +3, +6, +9, +12
(c) +4, +2, +1 ???
For pattern (c) each leap is the previous leap divided by 2
Therefore 2 divided by 1 = 0.5 so the next leap is +0.5
21 + 0.5 = 21.5
So ANS = 21.5

Is this solution Helpfull? Yes (17) | No (5)  

harish  (11 years ago)

4,2,5,9,5,11,13,7,16,17,9,21...
take first 3 digits...4,2,5
'4'-2='2'
'2'+3='5'
take next 3 digits... 9,5,11
'9'-4='5'
'5'+6='11'....
take next 3 digits... 13,7,16
'13'-6='7'
'7'+9 ='16'
take next 3 digits... 17,9,21
'17'-8='9'
'9'+12='21'
BUT we cant say the next 3 digits, unless one digit is given

Is this solution Helpfull? Yes (8) | No (4)  

Anandkumar  (11 years ago)

Seperate the given nos as set of 3 each as follows,
4, 2, 5 9, 5, 11 13, 7, 16 , 17, 9, 21 , ?
First no 1st set + 5 gives first no of second set as follows,
4+5=9
Similarly, 2+3=5, 5+6=11
From next series onwards use the no. by 1 less than the no. Added for the previous seris
I.e instead of using 5, 3, 6 use 4, 2, 5
Now u will get the following series
9+4=13, 5+2=7, 11+5=16
13+4=17, 7+2=9, 16+5=21
17+4=21, 9+2=11, 21+5=26
The new series is 21, 11, 26

Is this solution Helpfull? Yes (4) | No   

swati  (11 years ago)

arrange in 3 parts(4,2,5)(9,5,11)etc
4-(+2)-- 2 5
9---(+4)--- 5 11
13---(+6)--- 7 16
17---(+8)--- 9 21
21----(+10)----11

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