There are a total of 791 donkeys, cows, chickens and hens at a farm. The number of chickens was 315 more than the number of donkeys. The total number of cows and hens was 2 times the number of donkeys.
- How many cows and hens were there at the farm?
- The total number of legs for all the cows and hens was 540. How many cows were there in the farm?
(a)
Number of donkeys = 1 u
Number of cows and hens = 2 u
Number of chickens = 1 u + 315
Total number of animals
= 1 u + 2 u + 1 u + 315
= 4 u + 315
4 u + 315 = 791
4 u = 791 - 315
4 u = 476
1 u = 476 ÷ 4 = 119
Number of cows and hens
= 2 u
= 2 x 119
= 238
(b)
Number of
cows |
Number of
cows' legs |
Number of
hens |
Number of
hens' legs |
Total
|
238
|
238 x 4 =
952 |
0
|
0
|
952
|
237
|
237 x 4 =
948 |
1
|
1 x 2 =
2 |
950
|
32
|
32 x 4 =
128 |
206
|
206 x 2=
412 |
540
|
Total number of cows and hens = 238
Total number of legs if all of them are cows
= 238 x 4
= 952
Big difference in the total number of legs between the cows and the hens
= 952 - 540
= 412
Small difference in number of legs between one cow and one hen
= 4 - 2
= 2
Number of hens
= 412 ÷ 2
= 206
Number of cows
= 238 - 206
= 32
Answer(s): (a) 238; (b) 32
