15 is 4% of what number?

Remember that  4% means 0.04 .
Also remember that "of" almost always means"times".

So the problem really says      15  =  0.04  x  number

Divide each side of the equation by 0.04: 

                                             Number =  15/0.04  =  375

I'll do the first one for you. it isn't very hard at all.on number one, you have (50 × 3), which equals 150, and (3 × 3), which equals 9. after you establish that, you add 150 and 9 together. so, (150 + 9) equals 159.this means that 53 × 3 = 159.