MATH
posted by PLEASE HELP on .
Wendy answered 85% of the questions on her history test correctly. There were 40 questions on the test and all the questions had equal value. How many questions did Wendy NOT answer correctly on her test?

first you need to find 85% of 40 questions. turn 85% into the decimal .85... you do that by dividing 85 by 100. the formula is x=.85(40) and that gives you x=34. so now you know that Wendy had 34 out of 40 questions right, so now to find out how many she had wrong you subtract 34 from 40 and get 6. Wendy did not answer 6 questions correctly. Another faster way of doing this would be to realize since she had 85% right, then you know she had 15% wrong, so x=.15(40) , so x=6. Hope this helped.