There are a total of 673 sheep, donkeys, chickens and ducks at a farm. The number of chickens was 301 more than the number of sheep. The total number of donkeys and ducks was 2 times the number of sheep.
- How many donkeys and ducks were there at the farm?
- The total number of legs for all the donkeys and ducks was 568. How many donkeys were there in the farm?
(a)
Number of sheep = 1 u
Number of donkeys and ducks = 2 u
Number of chickens = 1 u + 301
Total number of animals
= 1 u + 2 u + 1 u + 301
= 4 u + 301
4 u + 301 = 673
4 u = 673 - 301
4 u = 372
1 u = 372 ÷ 4 = 93
Number of donkeys and ducks
= 2 u
= 2 x 93
= 186
(b)
Number of donkeys |
Number of donkeys' legs |
Number of ducks |
Number of ducks' legs |
Total
|
186
|
186 x 4 = 744 |
0
|
0
|
744
|
185
|
185 x 4 = 740 |
1
|
1 x 2 = 2 |
742
|
98
|
98 x 4 = 392 |
88
|
88 x 2= 176 |
568
|
Total number of donkeys and ducks = 186
Total number of legs if all of them are donkeys
= 186 x 4
= 744
Big difference in the total number of legs between the donkeys and the ducks
= 744 - 568
= 176
Small difference in number of legs between one donkey and one duck
= 4 - 2
= 2
Number of ducks
= 176 ÷ 2
= 88
Number of donkeys
= 186 - 88
= 98
Answer(s): (a) 186; (b) 98