Adam has a total of 7 chickens and goats.
The difference in their number of legs is 2.
How many (a) goats and (b) chickens does Adam have?
Number of
chickens |
Number of
chickens' legs |
Number of
goats |
Number of
goats' legs |
Difference in the
number of legs |
| 7 |
7 x 2 =
14 |
0 |
0 x 4 =
4 |
14 - 0 =
14 |
| 6 |
6 x 2 =
12 |
1 |
1 x 4 =
4 |
12 - 4 =
8 |
| 5 |
5 x 2 =
10 |
2 |
5 x 4 =
8 |
10 - 8 =
2 |
If all of the animals are chickens,
the number of legs needed
= 7 x 2
= 14
Total difference in the number of legs
= 14 - 2
= 12
Difference in the number of legs when 1 chicken is replaced by 1 goat
= 14 - 8
= 6
Number of goats
= 12 ÷ 6
= 2 (a)
Number of chickens
= 7 - 2
= 5 (b)
Answer(s): (a) 2; (b) 5
