Question

A steel pipe which was 16.84 feet long, weighed 20.88 pounds what is the weight of one foot of the steel pipe?

Answer 1

The weight of one foot of the steel pipe is 1.24 pounds or more accurately, 1.239905.... pounds.

This type of problem is solved using cross multiplication. You know the length (16.84 feet), and the weight (20.88 pounds), of the steel pipe. But what you do not know is the weight of one foot of the steel pipe. Since that is what we are solving for, the weight of one foot of the steel pipe will be our x variable.

This is how I set it up...

16.84 1
——— * ———
20.88 x

I came up with this equation. The length of the pipes I put in the numerator (top), and the weight I put in the denominator (bottom). Since 16.84 feet of a steel pipe weighs 20.88 pounds, 1 foot of a steel pipe weighs x pounds. After you have the equation set up you then move on to cross multiplication.

Step 1: Multiply the top number of the first fraction by the bottom number of the second fraction.
16.84*x= 16.84x

Step 2: Multiply the bottom number of the first fraction by the top number of the second fraction.
20.88*1=20.88

Step 3: Set the answers from step 1 and step 2 equal to each other.
16.84x=20.88

Step 4: Divide 16.88 on both sides so x is by itself.
16.84x 20.88
——— = ———
16.84 16.84

And after you divide on each side you have your answer which should be x=1.24