Your math marks decreased by 60% from the first quiz to the second quiz. If your marks in the third quiz were identical to those in the first quiz, by what percent did your marks increase from the second quiz to the third quiz ?
A. 60%
B. 75%
C. 100%
D. 150%
E. 250%
Let m be your marks in the first quiz.
Then, your marks are 0.4m in the second quiz and m in the third quiz.
Percent Increase
= (Marks in third Quiz - Marks in second quiz) x 100/Marks in second quiz
= (m - 0.4m) x 100 / 0.4m = (0.6/0.4) x 100 = 150.