Question

Pipe A and B can fill a tank in 24 and 30 hours respectively, however pipe C can empty it in X hours . pipe A and B are opened for 10 hours and then pipe C is opened.if ,tank is emptied in 90 hours ,then the find X value

Answer 1

Answer: 4/3

Step-by-step explanation:

Pipe A can fill in 24 hours .

∴ It can fill 1/24th of the tank in 1 hour .

Similarly Pipe B can fill 1/30th of the tank in 1 hour .

So pipes A and B together can fill  $\frac{1}{24} + \frac{1}{30}$ = $\frac{5 + 4}{120} = \frac{9}{120} = \frac{3}{40}$ or 3/40th of the tank in 1 hour .

Given that Pipe C can empty the tank in X hours .

∴ It can empty 1/X th of the tank in 1 hour .

Pipes A and B are both opened for 10 hours .

Hence in 10 hours they fill 3/40 * 10 = 30/40 or 3/4th of the tank .

Then Pipe C is opened , and it is given the tank is emptied in 90 hours .

After 90 hours , pipes A and B will fill 3/4 * 90 or 135/2th of the tank .

Since Pipe C empties 1/X every hour , in 90 hours , it will empty 90/X of the tank , and it is given that the tank gets emptied completely .

Hence $\frac{135}{2} = \frac{90}{X}$

=> 135X = 90 * 2

=> X = 180/135

=> X = 4/3

So the value of X is 4/3 .

Hope this helps you .

Please Mark this Brainliest .

Answer 2

Pipe A can fill 1/24th of the tank in 1 hr and pipe B can fill 1/30th of the tank in 1 hr.

Together they can fill the tank in 1hr = 1/24 +1/30 =9/120.

Pipe A and B opened for 100 hr (10hr+90hr because C empty the tank after 90 hr means pipe A and B still open for 90hr and filling the tank.)

A and B fill tank in 100 hr :

9/120×100 =15/2

Tank C empty the 15/2 in 90 hr,

15/2=90hr , therefore C can empty the whole tank in :

1=90×2/15

12 hr Ans.