Multiple choice general knowledge math & puzzles

A library contains 3 varieties of books: mystery, romance, and periodicals. There are a total of 150 books. There are 3 times as many mysteries as romance and twice as many periodicals as romance. How many of each variety are there?

  1. 75 mystery,25 romance,50 periodicals

  2. 50 mystery,75 romance,25 periodical

  3. 25 mystery,50 romance,75 periodical

  4. NONE

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let romance be R. Then mystery is 3R and periodicals are 2R. Total: R + 3R + 2R = 6R. Given 6R = 150, R = 25. Therefore, romance = 25, mystery = 75, and periodicals = 50. This matches the first option.