Abcd is a kite x = ?

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.

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

James was playing a game with his friends. he won 35 points. then he lost 15, lost 40 and won 55. how did he come out