104 is the answer to your problem
Answer:

Step-by-step explanation:
So say there are x yellow cubes.
Yellow = x
Blue = 3x
Green = 15x
It doesn't say red so I'm going to assume there are none.

A proper fraction is a fraction less than one, with the numerator less than the denominator so 1/2 is your answer
x is a variable. You need to find the variable to complete the equation.
ex. x = 1
x to the power of 5 (1x5x5x5x5x5)
1*x(0)=0
Three plus a number times two.