There are some donkeys, geese and donkeys in a farm.There are 3 times as many geese as donkeys. Marion finds out that among the animals, there are a total of 28 heads and 88 legs. How many donkeys are there?
Number of
4-legged animals |
Total legs of
4-legged animals |
Number of
2-legged animals |
Total legs of
2-legged animals |
Total legs |
28
|
28 x 4 =
112 |
0
|
0
|
112
|
27
|
27 x 4 =
108 |
1
|
1 x 2 =
2 |
110
|
16
|
16 x 4 =
64 |
12
|
12 x 2 =
24 |
24 |
Total number of legs if all are 4-legged animals
= 4 x 28
= 112
Big difference between all the 2-legged animals and all the 4-legged animals
= 112 - 88
= 24
Small difference between one 2-legged animal and one 4-legged animal
= 4 - 2
= 2
Number of geese
= 24 ÷ 2
= 12
Number of 4-legged animals
= 28 - 12
= 16
Number of donkeys = 1 u
Number of geese = 3 u
3 u = 12
1 u = 12 ÷ 3 = 4
Number of donkeys
= 1 u
= 4
Number of donkeys
= 16 - 4
= 12
Answer(s): 12
