Find the value of X. What does X=?

Aramp rises 4 feet over a distance of 10 feet. what is the length of the ramp?

What is the simplified form of square root of 400 to the 100th power ?

In the next 10 month,colin wants to save $900 for his vacation.he plans to save $75 each of the first 8 months. how much must he save each of the last 2 months in order to meet his goal if he saves the same amount each month ?