SOLUTION: Twin brothers, Billy and Bobby, can mow their grandparent's lawn together in 76 minutes. Billy could mow the lawn by himself in 35 minutes less time that it would take Bo
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-> SOLUTION: Twin brothers, Billy and Bobby, can mow their grandparent's lawn together in 76 minutes. Billy could mow the lawn by himself in 35 minutes less time that it would take Bo
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Question 1134521: Twin brothers, Billy and Bobby, can mow their grandparent's lawn together in 76 minutes. Billy could mow the lawn by himself in 35 minutes less time that it would take Bobby. How long would it take Bobby to mow the lawn by himself? Answer by ikleyn(52786) (Show Source):
Let x be that time for Bobby (the value under the problem's question).
Then the time for Billy alone is (x-35) minutes.
Now, Bobby makes of the job per minute,
while Billy makes of the job per minute.
Working together, they make + of the job per minute.
Their combined rate is exactly of the total job, which gives you an equation
+ = , (1)
and now it is your job to solve it !
The first step in solving is to multiply both sides of the equation (1) by 76*x*(x-35).
You will get a quadratic equation then, and I wish you to get a full success in solving it !
