There are some pigs, chickens and goats in a farm.There are 5 times as many chickens as goats. Fiona finds out that among the animals, there are a total of 28 heads and 72 legs. How many pigs 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
|
8
|
8 x 4 =
32 |
20
|
20 x 2 =
40 |
40 |
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 - 72
= 40
Small difference between one 2-legged animal and one 4-legged animal
= 4 - 2
= 2
Number of chickens
= 40 ÷ 2
= 20
Number of 4-legged animals
= 28 - 20
= 8
Number of goats = 1 u
Number of chickens = 5 u
5 u = 20
1 u = 20 ÷ 5 = 4
Number of goats
= 1 u
= 4
Number of pigs
= 8 - 4
= 4
Answer(s): 4
