Question 999089

Bob makes $4/hr more than Al, but only half of what Fred makes. Bob and Al work together for
10 hours and still make $12 less than Fred makes in 9 hours. What does Fred make per hour?
<pre>Let Fred’s per-hour pay be F
Then Bob makes: {{{(1/2)F}}}, or {{{F/2}}} per hour
Also, Al makes: {{{F/2 - 4}}} per hour
We then get:  {{{10(F/2 + F/2 - 4) = 9F - 12}}}
5F + 5F – 40 = 9F – 12
5F + 5F – 9F = - 12 + 40
10F – 9F = 28
F, or amount Fred makes, per hour = {{{highlight_green("$"28)}}}