Question

The ratio of the number of Chinese books to the number of English books in a bookshop was 4:5. After the shop owner bought another 30 Chinese books, there were twice as many Chinese books as English books. How many English books are there?

Answer 1

10 English books.

Explanation:

First, you would turn 4/5 into a fraction so you can use proportional relationships. Next you would multiply that by the number of Chinese and English books there. Half of 30 is 15 so, you would do 4/5*30/15, which would get you to 16/10. Since the denominator was the English book, there are 10 English book. Make sure to line up your factions so the units are the same when you multiply.