Problem:
The Fort Worth Zoo has a number of two-legged birds and a number of fourlegged mammals. On one visit to the zoo, Margie counted heads and legs. How many of the animals that Margie counted were two-legged birds?
.jpg)
Answer Choices:
A.
B.
C.
D.
E.
Solution:
All heads belonged to animals with at least two legs, accounting for of the legs. The additional legs belonged to four-legged mammals, each of which had two additional legs. So Margie saw fourlegged mammals and birds.
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions