Some hens and cows are in a farm. These animals have a total of 20 heads and 62 legs.
- How many cows are there?
- How many hens are there?
Number of cows |
Number of cows' legs |
Number of hens |
Number of hens' legs |
Total legs |
20
|
20 x 4 = 80 |
0
|
0
|
80 |
19
|
19 x 4 = 76 |
1
|
1 x 2 = 2 |
78
|
11 |
11 x 4 = 44 |
9
|
9 x 2 = 18 |
62
|
Number of legs if all are cows
= 20 x 4
= 80
Big difference between the number of legs of the cows and the hens
= 80 - 62
= 18
Small difference between the number of legs of one cow and one hen
= 4 - 2
= 2
Numbers of hens
= 18 ÷ 2
= 9
(b)
Number of cows
= 20 - 9
= 11
Answer(s): (a) 9; (b) 11