Two mechanics worked on a car. The first mechanic worked for 15
hours, and the second mechanic worked for 5
hours. Together they charged a total of $1550. What was the rate charged per hour by each mechanic if the sum of the two rates was $130 per hour?

Together they charged 1550. This means 1550 is made up of the first mechanics rate for 15 hours and the second's rate for 5 hours. Lets call the first's rate a, so he charges 15a. The second's let's call b. He charges 5b. We add them together 15a+5b=1550.

The Sum of the Rates

Since the first's rate is a and the second is b, we can write a+b=130 since their sum is 130.

We solve for a and b by substituting one equation into another. Solve for the variable. Then substitute the value into the equation to find the other variable.

For a+b=130, rearrange to b=130-a and substitute into 15a+5b=1550.

15a + 5 (130-a)=1550

15a+650-5a=1550

10a+650-650=1550-650

10a=900

a=$90 was charged by the first mechanic.

We substitute to find the second mechanic's rate.

90+b=130

90-90+b=130-90

b= $40 was charged by the second mechanic

Two mechanics worked on a car. The first mechanic worked for 15 hours, and the second mechanic worked for 5 hours. Together they charged a total of $1550. What was the rate charged per hour by each mechanic if the sum of the two rates was $130 per hour?

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Two mechanics worked on a car. The first mechanic worked for 15
hours, and the second mechanic worked for 5
hours. Together they charged a total of $1550. What was the rate charged per hour by each mechanic if the sum of the two rates was $130 per hour?