Anil grows tomatoes in his backyard which is in the shape of a square. Each tomato takes 1 cm2 in his backyard. This year, he has been able to grow 131 more tomatoes than last year. The shape of the backyard remained a square. How many tomatoes did Anil produce this year?  Choose the correct choice.
A) 4225  B) 4096  C) 4356  D) insufficient data  E) none of these

Rationale: detailed solution let the area of backyard be x 2 this year and y 2 last year ∴ x 2 - y 2 = 131 = ) ( x + y ) ( x - y ) = 131 now , 131 is a prime number ( a unique one too . check out its properties on google ) . also , always identify the prime number given in a question . might be helpful in cracking the solution . = ) ( x + y ) ( x - y ) = 131 x 1 = ) x + y = 131 x - y = 1 = ) 2 x = 132 = ) x = 66 and y = 65 ∴ number of tomatoes produced this year = 662 = 4356 correct choice ( c )
Answer: C