Use proportions to solve real world math problems

Question

Marcos paid $1.12 for a dozen eggs from a person who was selling eggs filled with flour. He later learned that he needed 3 more eggs. How much will he pay for the 3 extra eggs?

Answer 1

Assuming Marcos can buy 3 eggs for the same price per egg as the dozen he bought, we can solve for the price per egg and multiply this by 3 to get our answer.

He paid $1.12 for 12 eggs, so to find the price of one egg, we simply divide $1.12 by the number of eggs that were bought with this amount:

$1.12 / 12 = $0.09333 (repeating 3's)

This is our price per egg (less than 10 cents)

Now we find how much three of these eggs will cost by multiplying this number by 3:

0.093333 x 3 = 0.28 cents

Once you understand this process, another way to solve this more quickly is to divide the original amount of eggs by the number he will purchase: 12 / 3 = 4 and then divide the price of 12 eggs by this number:

$1.12 / 4 = 0.28 cents