Some ducks and pigs are in a farm. These animals have a total of 17 heads and 56 legs.
- How many pigs are there?
- How many ducks are there?
Number of pigs |
Number of pigs' legs |
Number of ducks |
Number of ducks' legs |
Total legs |
17
|
17 x 4 = 68 |
0
|
0
|
68 |
16
|
16 x 4 = 64 |
1
|
1 x 2 = 2 |
66
|
11 |
11 x 4 = 44 |
6
|
6 x 2 = 12 |
56
|
Number of legs if all are pigs
= 17 x 4
= 68
Big difference between the number of legs of the pigs and the ducks
= 68 - 56
= 12
Small difference between the number of legs of one pig and one duck
= 4 - 2
= 2
Numbers of ducks
= 12 ÷ 2
= 6
(b)
Number of pigs
= 17 - 6
= 11
Answer(s): (a) 6; (b) 11