(This is a word problem) You are making up your own mix of concrete to patch a set of stairs. In order to have the proper mix, you need to mix 1 part of Portland cement with 2 parts of sand and 3 parts of gravel. a. How many total parts are in one batch of concrete?
b. You make a mix with 4 parts of sand. How many total parts cement, sand, and gravel are in your mix?