There are some donkeys, ducks and goats in a farm.There are 3 times as many ducks as goats. Gabby finds out that among the animals, there are a total of 26 heads and 80 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 |
26
|
26 x 4 =
104 |
0
|
0
|
104
|
25
|
25 x 4 =
100 |
1
|
1 x 2 =
2 |
102
|
14
|
14 x 4 =
56 |
12
|
12 x 2 =
24 |
24 |
Total number of legs if all are 4-legged animals
= 4 x 26
= 104
Big difference between all the 2-legged animals and all the 4-legged animals
= 104 - 80
= 24
Small difference between one 2-legged animal and one 4-legged animal
= 4 - 2
= 2
Number of ducks
= 24 ÷ 2
= 12
Number of 4-legged animals
= 26 - 12
= 14
Number of goats = 1 u
Number of ducks = 3 u
3 u = 12
1 u = 12 ÷ 3 = 4
Number of goats
= 1 u
= 4
Number of donkeys
= 14 - 4
= 10
Answer(s): 10
