Alex scored a 75% on his history test. If he correctly answered 18 questions, how many questions did Alex answer incorrectly?

Answer 1

Hi Rae,

The first thing we want to do is set up an equation for this situation, and it would be helpful to first figure out the total number of questions. In this situation, Alex correctly answered 75% OF some amount of questions to get 18 correctly. We can convert 75% to decimal form, which is .75. Whenever we see the word OF, it means we are going to multiply. So, the equation would be 0.75x (x representing the total amount of questions) = 18. Then, we solve for X by dividing 18 by .75. We find out that there were 24 total questions on the exam. Since there were 24 total questions and Alex answered 18 correctly, he must have answered 6 incorrectly.

Hope this helps!