The ratio of the number of geese in Farm B to the number of geese in Farm C was 3 : 5. There were 70 more geese in Farm C than in Farm B. When 10 geese escaped from Farm C, the farmer in Farm C bought another 15 geese. What was the new ratio of the number of geese in Farm B to the number of geese in Farm C in the end? Give your answer in the simplest form.
| |
Farm B |
Farm C |
| Before |
3 u |
5 u |
| Change 1 |
|
- 10 |
| Change 2 |
|
+ 15 |
| After |
3 u |
5 u + 5 |
Number of more geese in Farm C than Farm B
= 5 u - 3 u
= 2 u
2 u = 70
1 u = 70 ÷ 2 = 35
Number of geese in Farm B
= 3 u
= 35 x 3
= 105
Number of geese in Farm C
= 5 u
= 35 x 5
= 175
New number of geese in Farm C
= 5 u + 5
= 175 + 5
= 180
Farm B : Farm C
105 : 180
(÷ 15)7 : 12
Answer(s): 7 : 12
