Is AB congruent to CB?

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

Maurice has 54 fewer comic books than rebecca.they have 130 comic books together .how many comic books are in maurices collection ? how many comic books are in rebeccas collection

Twelve less than a number is at most 20