Question

5,10,26,50,? Find next value in given series.

Answer 1

Grouping of terms

We will group the data in groups of 2 . For example it will be of the form ( a,b ) where a and b have a relation .

( 5,10 )

( 10,26 )

( 26,50 )

Find the relation

Now we will find the relation .

Subtract 1 from each data .

( 4 , 9 )

( 9 , 25 )

( 25 , 49 )

Now we see that each number is a perfect square .

2² = 4

3² = 9

4² = 16 ( not there )

5² = 25

6²= 36 ( not there )

7² = 49

Following this : 8² should not be there .

9² = 81 should be there .

Add 1 to the value .

81 + 1 = 82

Hence the next number should be 82 .