Prof. Suman takes a number of quizzes for a course. All the quizzes are out of 100. A student can get an A grade in the course if the average of her scores is more than or equal to 90. Grade B is awarded to a student if the average of her scores is between 87 and 89 (both included). If the average is below 87, the student gets a C grade. Ramesh is preparing for his last quiz and he realizes that he must score a minimum of 97 to get an A grade. After the quiz, he realizes that he will score 70, and he will just manage a B. how many quizzes did Prof. Suman take?

A. 6

B. 7

C. 8

D. 9

E. None of these

Answer: Option D

Solution(By Examveda Team)

The difference between just getting an A grade and just getting a B grade would be equal to (number of quizzes × 3).
The difference between the required score to manage an A grade and the score achieved to just manage a B grade as given in the problem’s information is equal to 97 – 70 = 27
Thus, number of quizzes × 3 = 27
Hence, number of quizzes is 9