A recipe for cookies calls for 4 eggs. The recipe makes 6 dozen cookies. how many eggs would be need to make 21 dozen cookies?

5 answers

4 / 6 : x / 21

Cross multiply.

We'll be glad to check your answer.
63 eggs?
No, from the proportion, you should see that x will be less than 21, not more.

4/6 : x/21 cross-multiplied ~~> 4*21=6x

Now solve for x. Multiply 4*21 and then divide both sides by 6. What's the answer?
14 eggs!
Right! :-)