Question

FIND THE MISSING NUMBER
4 8 20
19 2 ?
7 20 113
A.15 B.17 C.19 D.21

Answer 1

solution :
     4 8 20
     19 2 ?
     7 20 113
Logic here is as follows
        third term in a row = first term*second term - first term +second term
                    therefore missing term is
                        = 19*2 - 19+2 = 38 - 21 = 17

Hence the answer is 17
Hope this helps you!!! 

Answer 2

For finding the missing we can simplify as follows
        third term in a row  is equal to first term multiply second term  minus first term  plus second term
So the answer is 17