There are 4 times as many donkeys as ducks.
There are 450 legs altogether.
- Find the number of animals.
- Find the number of less ducks than donkeys.
- Find the number of less ducks' legs than donkeys' legs.
| |
Donkeys |
Ducks |
Total |
Number
(Number of animals) |
4 u |
1 u |
5 u |
Value
(Number of legs) |
4 |
2 |
|
Total value
(Total number of legs) |
4 x 4 =
16 u |
1 x 2 =
2 u |
18 u |
(a)
Let the number of ducks be 1 u.
Number of donkeys = 4 u
Number of donkeys' legs = 4 x 4 u = 16 u
Number of ducks' legs = 2 x 1 u = 2 u
Total number of legs = 16 u + 2 u = 18 u
18 u = 450
1 u = 450 ÷ 18 = 25
Number of animals
= 4 u + 1 u
= 5 u
= 5 x 25
= 125
(b)
Number of less ducks than donkeys
= 4 u - 1 u
= 3 u
= 3 x 25
= 75
(c)
Number of less ducks' legs than donkeys' legs
= 16 u - 2 u
= 14 u
= 14 x 25
= 350
Answer(s): (a) 125; (b) 75; (c) 350
