SOLUTION: two hoses,one of which has a flow-rate three times the other, can together fill a tank in 3 hours. How long does it take each of the hoses individually to fill the tank?

Hi,

Let x be the low-rate of one hose.  Then 3x would the low-rate of the other

question states following (using "in 1hr's time" as the equalizer)



Multiplying both sides of the equation by 3x so as all denominators are 1

3 + 1 = x

4 = x

on hose can fill the tank in 4 hrs the other in (3*4) or 12 hrs

checking our answer

1/4  + 1/12 =  4/12 =1/3