There are a total of 680 cows, donkeys, hens and chickens at a farm. The number of hens was 300 more than the number of cows. The total number of donkeys and chickens was 2 times the number of cows.
- How many donkeys and chickens were there at the farm?
- The total number of legs for all the donkeys and chickens was 424. How many donkeys were there in the farm?
(a)
Number of cows = 1 u
Number of donkeys 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 = 680
4 u = 680 - 300
4 u = 380
1 u = 380 ÷ 4 = 95
Number of donkeys and chickens
= 2 u
= 2 x 95
= 190
(b)
Number of
donkeys |
Number of
donkeys' legs |
Number of
chickens |
Number of
chickens' legs |
Total
|
190
|
190 x 4 =
760 |
0
|
0
|
760
|
189
|
189 x 4 =
756 |
1
|
1 x 2 =
2 |
758
|
22
|
22 x 4 =
88 |
168
|
168 x 2=
336 |
424
|
Total number of donkeys and chickens = 190
Total number of legs if all of them are donkeys
= 190 x 4
= 760
Big difference in the total number of legs between the donkeys and the chickens
= 760 - 424
= 336
Small difference in number of legs between one donkey and one chicken
= 4 - 2
= 2
Number of chickens
= 336 ÷ 2
= 168
Number of donkeys
= 190 - 168
= 22
Answer(s): (a) 190; (b) 22
