Aptitude - Odd Man Out and Series - Discussion

Discussion Forum : Odd Man Out and Series - Pick Wrong No. (Q.No. 5)
Directions to Solve
Find out the wrong number in the given sequence of numbers.

5.
1, 2, 6, 15, 31, 56, 91
31
91
56
15
Answer: Option
Explanation:

1, 1 + 12 = 2, 2 + 22 = 6, 6 + 32 = 15, 15 + 42 = 31, 31 + 52 = 56, 56 + 62 = 92

Last number of given series must be 92 not 91.

Discussion:
22 comments Page 2 of 3.

Saran said:   1 decade ago
Answer is 91 but calculate answer is 92. So it is a wrong no.

Riya said:   1 decade ago
According to me 31 should be the answer because its the only prime no in the question?

Moni said:   1 decade ago
What is the answer for sum?

Debasish said:   1 decade ago
6-2 = 4 = 2*2.
15-6 = 9 = 3*3.
31-15 = 16 = 4*4.
56-31 = 25 = 5*5.
91-56 = 35! = 6*6.

Sreeram said:   10 years ago
Why not 31? It's the only prime number.

Manish said:   9 years ago
If we see prime numbers. Then 31 will be the answer. So which is the correct answer?

Arthy said:   9 years ago
2 - 1 = 1(odd),
6 - 2 = 4(even),
15 - 6 = 9(odd),
31 - 15 = 16(even),
56 - 31= 25(odd),
But 91 - 56 = 45 (odd) so that 91 is the wrong number here.
(6)

Fathima said:   9 years ago
31 is the only prime number.

Why not the answer is 31? Some one explain.

Aditya said:   9 years ago
2, 5, 15, 131, 530, 13257 find out wrong number of the series.

Jatin Dwivedi said:   8 years ago
Answer should be 31.


Post your comments here:

Your comments will be displayed after verification.