Problema Solution
Jack can mow the lawn in 4 hours. Jill can mow the same lawn in 3 hours. How much time would it take for them to mow the lawn together?
Answer provided by our tutors
RateJack = 1mow/4hr = 0.25 mow/hr
RateJill = 1mow/3hr = 0.33 mow/hr
Qty = Rate * Time = (RateJack + RateJill) * Time
Time = Qty/Rate
Time = 1mow/ (RateJack + RateJill) = 1mow/ (1mow/4hr + 1mow/3hr)
Time = 1/(1/4 + 1/3) = 1/(0.25 + 0.33) = 1/(0.58mow/hr) = 1.72hr