Hi there can anyone me out with this that is really good in math

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.

The pyramid below was dissected by a horizontal plane which shape describes the pyramid horizontal cross section

Look at triangle wxy what is the length (in centimeters) of the side wy of the triangle?