+41 Recently, Frank took a one-hundred question aptitude test where each correct answer scored 7 points, each incorrect answer scored -2 points, and each question not answered scored zero points. Frank answered 90 questions and scored 495 points. How many questions did he answer correctly?
Thank you so much!
+130071 Let the questions he answered correctly = x
Let the one he answered incorrectly = 90 - x
{ the ones he didn't answer don't matter since they add nothing to the total points }
So
7x - 2(90 - x) = 495
7x - 180 + 2x = 495
9x - 180 = 495
9x = 495 + 180
9x = 675
x = 675 / 9 = 75 answered correctly
