A recipe for oatmeal raisin cookies calls for 1 2/3 cups of flour to make 4 dozen cookies. How many cups of flour are needed to make 6 dozen cookies?

Hi there! So, you need 1 2/3 cups of flour to make 4 dozens of oatmeal raisin cookies. To find the unit rate of the amount of flour needed per dozen, let’s divide. 5/3 / 4. To divide fractions, keep the first fraction the same, change division into multiplication, and flip the second fraction over. Then, this would be 5/3 * 1/4. Now, multiply straight across. 5/3 * 1/4 is 5/12. 5/12 cup of flour is needed per dozen. To find the amount for 6 dozens, let’s multiply by 6. Multiply the amount needed per dozen by the number of dozens, in this case, 6. 5/12 * 6/1 is 30/12 or 2 1/2 in simplest form. 2 1/2 cups of flour are needed to make 6 dozen cookies.