What is the simplest form of 8 cups to 36 cups

The difference of 2 numbers is 21 and the quotient of the equation is 4 then what are the two numbers?

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

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.