There are 4 times as many dogs as pigeons.
There are 90 legs altogether.
- Find the number of animals.
- Find the number of less dogs than pigeons.
- How many more dogs' legs are there than pigeons' legs?
| |
Dogs |
Pigeons |
Total |
Difference |
| Number (Animals) |
4 u |
1 u |
5 u |
3 u |
| Value (Legs) |
4 |
2 |
|
|
| Total value (Total legs) |
16 u |
2 u |
18 u |
14 u |
$
Choose the animal type with a smaller number to be 1 u.
Let the number of pigeons be 1 u.
Number of pigeons = 1 u
Number of dogs = 4 u
Number of pigeons' legs = 2 x 1 u = 2 u
Number of dogs' legs = 4 x 4 u = 16 u
Total number of legs
= 16 u + 2 u
= 18 u
18 u = 90
1 u = 90 ÷ 18 = 5
(a)
Number of animals
= 4 u + 1 u
= 5 u
= 5 x 5
= 25
(b)
Number of less dogs than pigeons
= 4 u - 1 u
= 3 u
= 3 x 5
= 15
(c)
Number of more dogs' legs than pigeons' legs
= 16 u - 2 u
= 14 u
= 14 x 5 = 70
Answer(s): (a) 25; (b) 15; (c) 70
