Yesterday, there were four times as many ducks as cows on a farm. Today, 77 ducks are sold. There are thrice as many cows now. Find the total number of cows and ducks on the farm yesterday.
| |
Ducks |
Cows |
Total |
| Before |
4x3 =
12 u |
1x3 =
3 u |
15 u |
| Change |
- 77 |
|
|
| After |
1 u |
3 u |
|
The number of cows at first and in the end remains unchanged. Make the number of cows the same. LCM of 1 and 3 is 3.
Number of ducks sold
= 12 u - 1 u
= 11 u
11 u = 77
1 u = 77 ÷ 11 = 7
Total number of cows and ducks yesterday
= 12 u + 3 u
= 15 u
= 15 x 7
= 105
Answer(s): 105
