Some ducks and donkeys are in a farm. These animals have a total of 18 heads and 60 legs.
- How many donkeys are there?
- How many ducks are there?
Number of
donkeys |
Number of
donkeys' legs |
Number of
ducks |
Number of
ducks' legs |
Total legs |
18
|
18 x 4
= 72 |
0
|
0
|
72 |
17
|
17 x 4
= 68 |
1
|
1 x 2
= 2 |
70
|
| 12 |
12 x 4
= 48 |
6
|
6 x 2
= 12 |
60
|
Number of legs if all are donkeys
= 18 x 4
= 72
Big difference between the number of legs of the donkeys and the ducks
= 72 - 60
= 12
Small difference between the number of legs of one donkey and one duck
= 4 - 2
= 2
Numbers of ducks
= 12 ÷ 2
= 6
(b)
Number of donkeys
= 18 - 6
= 12
Answer(s): (a) 6; (b) 12
