12 of the number of cows that Farmer Bobby had was equal to
57 of the number of cows that Farmer Luis had. When Farmer Bobby sold 300 of his cows and Farmer Luis bought another 40, the ratio of the number of cows that Farmer Bobby had to the number of cows Farmer Luis had become 5 : 4. What was the total number of cows that the 2 farmers had at first?
|
Make p the same (1) x 4 = (3) |
Farmer Bobby (1) |
Farmer Luis (2) |
Make p the same (2) x 5 = (4) |
Before |
40 u |
10 u |
7 u |
35 u |
Change |
- 1200 |
- 300 |
+ 40 |
+ 200 |
After |
20 p |
5 p |
4 p |
20 p |
Make the numerators the same.
1x52x5 Farmer Bobby's cows =
5x17x1 Farmer Luis's cows
510 Farmer Bobby's cows =
57 Farmer Luis's cows
40 u - 1200 = 35 u + 200
40 u - 35 u = 200 + 1200
5 u = 1400
1 u = 1400 ÷ 5 = 280
Total number of cows that the 2 farmers had
= 10 u + 7 u
= 17 u
= 17 x 280
= 4760
Answer(s): 4760