Question

A gardening club has 21 members, of which 13 are males and the rest are females. What is the ratio of females to all club members

Answer 1

1. Find out how many females there are by subtracting the total members (21) minus the males (13). 21 - 13 = 8.
2. It is asking for a ratio of females (8) to total club members (21). A ratio can be written with a colon, as a fraction, or with the word "to". Any of these answers would work:

8:21
8/21
8 to 21

Answer 2

If 13 are males that means that 8 are females. The ratio of females to all club members would be 8:21