What is the decay factor that corresponds to a product that decreases its value first by 20%, and than decreases by 40% of its value, and finally decreases by 62% of its value?

When solving this problem: 3025/5.5 = a/90.75 you get 49912.5 which would be the length of one of the sides of a square when the area is only 90.75 inches. is that answer correct, why, and how is it possible?

If f(x)=x+7 and g(x)=1/x what is (fog)(x)

Iknow the square root of 2 is irrational