The ratio of the number of ducks in Farm B to the number of ducks in Farm C was 3 : 5. There were 60 fewer ducks in Farm B than in Farm C. When 9 ducks escaped from Farm C, the farmer in Farm C bought another 13 ducks. What was the new ratio of the number of ducks in Farm B to the number of ducks in Farm C in the end? Give your answer in the simplest form.
| |
Farm B |
Farm C |
| Before |
3 u |
5 u |
| Change 1 |
|
- 9 |
| Change 2 |
|
+ 13 |
| After |
3 u |
5 u + 4 |
Number of fewer ducks in Farm B than Farm C
= 5 u - 3 u
= 2 u
2 u = 60
1 u = 60 ÷ 2 = 30
Number of ducks in Farm B
= 3 u
= 30 x 3
= 90
Number of ducks in Farm C
= 5 u
= 30 x 5
= 150
New number of ducks in Farm C
= 5 u + 4
= 150 + 4
= 154
Farm B : Farm C
90 : 154
(÷ 2)45 : 77
Answer(s): 45 : 77
