1) Mio can build a large shed in 15 days less than Yuuko can. If they build it together, it would take them 18 days. How long would it take each of them working alone?

Question

M: Y:

2) A sink can be filled by a pipe in 6 minutes but it takes 12 minutes to drain a full sink. If both the pipe and the drain are open, how long will it take to fill the sink?

Answer 1

a)

ratecombined=rateM+rateY
shed/18 = shed/(timeY-15) + shed/timeY

Y* (Y-15)=18( Y + (y-15))
y^2-15Y=36Y-270
y^2-51Y+270=0
(y-45)(Y-6)=0

y=45, M=30