SOLUTION: a recent safaria had people dand elephants there were 100 knees and 100 trunks each person took 3 trunks. how many people and elephants were there?

Algebra ->  Inverses -> SOLUTION: a recent safaria had people dand elephants there were 100 knees and 100 trunks each person took 3 trunks. how many people and elephants were there?      Log On


   



Question 151619: a recent safaria had people dand elephants there were 100 knees and 100 trunks each person took 3 trunks. how many people and elephants were there?
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
In order to solve this problem, one must assume that there are no 1-legged people or 3-legged elephants in the group, i.e. all of the people have 2 legs and therefore 2 knees, and all of the elephants have 4 legs and therefore 4 knees. You also have to assume that there are no elephants which, for whatever reason, have a different number of trunks than 1. Given all of that:

x is the number of people
y is the number of elephants

Then:
2x is the number of knees attributible to people and
4y is the number of knees attributible to elephants.

Since there are 100 knees, 2x+%2B+4y+=+100

By similar analysis, 3x%2By=100 is the equation that represents the distribution of trunks of both kinds (elephant proboscises and containers for personal belongings).

Your task is then to solve this system of two linear equations in two variables. I recommend the elimination method for this problem.

Hint: Multiply the 2nd equation by -4.