Question

A swimming pool is filled with water by using two taps A and B. Alone, it takes tap A 3 hours less than B to fill the same pool. Together, they take 2 hours to fill the pool. How many hours does it take each tap to fill the swimming pools separately?

Answer 1

Tap A 3hrs

Tap B 6hrs

Explanation:

Let the volume of the swimming pool be Xm^3.

Now, to get the appropriate volume, we know we need to multiply the rate by the time. Let the rate of the taps be R1 and R2 respectively, while the time taken to fill the swimming pool be Ta and Tb respectively.

x/Ta= Ra

x/Tb= Rb

X/(Ra + Rb)= 2

Ta = Tb - 3

From equation 2:

X = 2( Ra + Rb)

Substituting the values of Ra and Rb Using the first set of equations

X = 2( x/Ta + x/Tb)

But Ta = Tb - 3

1/2 = 1/(Tb - 3)+ 1/Tb

0.5 = (Tb + Tb-3)/Tb(Tb - 3)

At this juncture let’s say Tb = y

0.5 = (2y - 3)/y(y - 3)

y(y-3 ) = 4y - 6

y^2 -3y - 4y + 6 = 0

y^2 -7y + 6= 0

Solving the quadratic equation, we get y =

y = Tb = 6hrs or 1hr

We remove one hour as we know that Tap A takes 3hrs left than tap B and there is nothing like negative hours

Now, we get Ta by Tb -3 = 6 - 3 = 3hrs