Aptitude - Odd Man Out and Series - Discussion

64 is a perfect square out of these numbers.

Difference between each number is odd like 3, 5, 7, 9. And last two numbers difference is even.

Addition of prime number to previous digit.

3, 5, 7, 9, 11, 13.

Odd place even no, even place odd no. But 64 is even.

Its very simple just follow this, just go on subtracting.

2, 5, 10, 17, 26, 37, 50, 64.

5-2=3.
10-5=5.
17-10=7.
26-17=9.
37-26=11.
50-37=13.

But 64-50 is equal to 14. We have seen that the order is 3, 5, 7, 9, 11, 13.

All are odd numbers but 14 is an even number. So finally the answer is 64.

The answer can be solved out in two ways:

1) The series is continued by first squaring the numbers from 1 and then next we have to add one the squared numbers and so on. By which 64 is the only number in the series written without adding 1 to it after squared.

2) We can also solve in the another way. Add the subsequent odd numbers from 3 to the given series but we find 65 is obtained in place of 65 by adding 15 to 50.

Therefore it can be judged that 64 is the odd man out.

37 can be the right answer because it is odd digit.

Only 64 is perfect square.

In between 2and 5 there are two numbers i.e., 3, 4.

Similarly 5 and 10 there are four numbers i.e., 6, 7, 8, 9.

Between 10 and 17 there are six numbers i.e., 5, 11, 12, 13, 14, 15, 16.

Similarly, the order is increased like 2, 4, 6, 8, 10, 12, 14.

But the last two numbers 50 and 64 there are only 13 numbers.

So the answer is 64.

2 + 3 = 5.
5 + 5 = 10.
10 + 7 = 17.
And so on.