Christine is building a deck in her backyard. in order to place the
posts, she will make concrete using a mixture. the mix requires 1 part
water to 2 parts cement to 3 parts sand. the relationship between
water, cement, and sand is proportional. if she has 25 pounds of
cement and will use it all, how many pounds of sand will she need?
one gallon of water weighs about 8.34 pounds. how many gallons of
water will she need? round to the nearest tenth.