smc

Question

At the beginning of the school year, Lisa's goal was to earn an A on at least 80% of her 50 quizzes for the year. She earned an A on 22 of the first 30 quizzes. If she is to achieve her goal, on at most how many of the remaining quizzes can she earn a grade lower than an A?

Accepted Answer

Lisa's goal was to get an A on 80% 50 = 40 quizzes. She already has A's on 22 quizzes, so she needs to get A's on 40-22=18 more. There are 50-30=20 quizzes left, so she can afford to get less than an A on 20-18=2 of them. Here, only the A's matter... No complicated stuff!