Four- sevenths of the children in class earned A's on the last math test. 18 children did not earn an A. How many earned A's?

Question

Four- sevenths of the children in class earned A's on the last math test. 18 children did not earn an A. How many earned A's?

Answer 1

Hello Alyssa.

If 4/7 of the class get A then 1 -4/7 = 3/7 of the class did not get A

Lets say there are x students in that class;

x*3/7 = 18.

3x = 18*7. (cancel denominator by multiplying it both sides)

3x = 126. (cancel 3)

x = 42

if 4/7 of the class get A; 4/7*42 = 24 of them get A

hope that helps