There are a total of 724 donkeys, cows, hens and chickens at a farm. The number of hens was 300 more than the number of donkeys. The total number of cows and chickens was 2 times the number of donkeys.
- How many cows and chickens were there at the farm?
- The total number of legs for all the cows and chickens was 616. How many cows were there in the farm?
(a)
Number of donkeys = 1 u
Number of cows and chickens = 2 u
Number of hens = 1 u + 300
Total number of animals
= 1 u + 2 u + 1 u + 300
= 4 u + 300
4 u + 300 = 724
4 u = 724 - 300
4 u = 424
1 u = 424 ÷ 4 = 106
Number of cows and chickens
= 2 u
= 2 x 106
= 212
(b)
Number of cows |
Number of cows' legs |
Number of chickens |
Number of chickens' legs |
Total
|
212
|
212 x 4 = 848 |
0
|
0
|
848
|
211
|
211 x 4 = 844 |
1
|
1 x 2 = 2 |
846
|
96
|
96 x 4 = 384 |
116
|
116 x 2= 232 |
616
|
Total number of cows and chickens = 212
Total number of legs if all of them are cows
= 212 x 4
= 848
Big difference in the total number of legs between the cows and the chickens
= 848 - 616
= 232
Small difference in number of legs between one cow and one chicken
= 4 - 2
= 2
Number of chickens
= 232 ÷ 2
= 116
Number of cows
= 212 - 116
= 96
Answer(s): (a) 212; (b) 96