There are 7 animals in an enclosure. Some are ducks and the others are dogs. Andy counts a total of 20 legs.
- How many dog are there?
- How many ducks are there?
(a)
If all of the animals are ducks,
number of legs needed for ducks
= 7 x 2
= 14
Extra legs needed for each dog
= 4 - 2
= 2
Total extra legs needed for all the dog
= 20 - 14
= 6
Number of dog
= 6 ÷ 2
= 3
(b)
Number of ducks
= 7 - 3
= 4
Answer(s): (a) 3; (b) 4