Question

3,4,7,13,?,38 find the missing​

Answer 1

(i) 3 , 4 , 7 , 13 , ? , 38

Take difference between numbers

(ii) (4-3) , (7-4) , (13-7)

1 , 3 , 6

Take difference between numbers again

(iii) (3-1) , (6-3)

2 , 3

This is a pattern you might recognise

2 , 3 , 4 , 5....

The above pattern is being followed in pattern (iii)

So the pattern (ii) can be wriiten as

$1 ,3^{(1+2)} , 6^{(3+3)} , 10^{(6+4)},....$

So the pattern (i) is

3 , 4 , 7 , 13 , 23 , 38

So missing number is 23