Atree casts a shadow 32 feet long .the angle of elevation of the sun is 62° what is the height of the tree

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.

Can anyone me with this question?

Perform the indicated operation. y^2 + 3y - 10 / 3y + 15