Question

300 is 100% of what number?

Answer 1

300/x=100/100
(300/x)*x=(100/100)*x       - we multiply both sides of the equation by x
300=1*x       - we divide both sides of the equation by (1) to get x
300/1=x 
300=x 
x=300

now we have: 
100% of 300=300

The answer is 300