SOLUTION: 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 h
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10 hours and still make $12 less than Fred makes in 9 hours. What does Fred make per h
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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? Found 2 solutions by Theo, MathTherapy:Answer by Theo(13342) (Show Source):
let b = how much bob makes per hour.
let a = how much al makes per hour.
let f = how much fred makes per hour.
you are given that:
b = a+4
b = f/2
(b+a)*10 = f*9-12
make a and f in terms of b and you can then solve for b.
since b = a + 4, then a = b - 4
since b = f/2, then f = 2 * b
the equation you want to solve is:
(b+a)*10 = f*9-12
raplace a with b-4 and replace f with 2b, and you get:
(b + b - 4) * 10 = 2b * 9 - 12
simplify to get:
(2b-4)*10 = 18b - 12
simplify further to get:
20b - 40 = 18b - 12
subtract 18b from both sides of this equation and add 40 to both sides of this equation to get:
2b = 28
solve for b to get b = 14.
since a = b-4, then a = 10
since f = 2b, then f = 28
your numbers are:
b = 14
a = 10
f = 28
b = a + 4 becomes 14 = 10 + 4 which is true.
b = f/2 becomes 14 = 28/2 which is true.
(b+a)*10 = f*9-12 becomes (14+10)*10 = 28*9 - 12 which becomes:
24 * 10 = 28 * 9 - 12 which becomes:
240 = 252 - 12 which becomes:
240 = 240 which is true.
all givens are confirmed to be true when b = 14, a = 10, and f = 28.
those are your solutions.
you were asked what fred makes per hour.
your answer is that fred makes 28 dollars per hour.
You can put this solution on YOUR website!
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?
Let Fred’s per-hour pay be F
Then Bob makes: , or per hour
Also, Al makes: per hour
We then get:
5F + 5F – 40 = 9F – 12
5F + 5F – 9F = - 12 + 40
10F – 9F = 28
F, or amount Fred makes, per hour =
