Problem: the greatest number which on dividing 1657 and 2037 leaves remainders 9 and 5 respectively , is :
Rationale: "explanation : required number = h . c . f . of ( 1657 - 9 ) and ( 2037 - 5 ) = h . c . f . of 1648 and 2032 = 16 . answer : a"
annotated_formula: gcd(subtract(2037, 5), subtract(1657, 9))