Which of the following would you use as the percent equation to determine that 30 is 90 percent of what number?

A.) a = 0.3 times 90
B.) 90 = 0.3 times a
C.) a = 0.9 times 30
D.) 30 = 0.9 times a

Question

Which of the following would you use as the percent equation to determine that 30 is 90 percent of what number? 

A.) a = 0.3 times 90
B.) 90 = 0.3 times a
C.) a = 0.9 times 30
D.) 30 = 0.9 times a

anonymous · Answer

translate in to math 
30 is 90% of what number
30 is the number 30
"is" means equals
"90%" means 0.9
"of" means times 
"what number" is a variable, they are using $a$
$$30=0.9\times a$$