Can u pls help me answer this math problem?

Question

A swimming pool can be filled by an inlet pipe in 8 hrs & emptied by an outlet pipe in 10 hrs. One day the pool is empty and the owner opens the inlet pipe to fill the pool. But she forgets to close the outlet with both pipes open. How long will it take to fill the pool?

I will vote for the best answer here....tnx.

Answer 1

Let

1/8x = Inlet pipe

1/10x = Outlet pipe

1 = The total time

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1/8x - 1/10x = 1

40(1/8x) - 40(1/10x) = 40(1)

5x - 4x = 40

x = 40

The answer is x = 40

It will take 40 hours to fill the pool

Insert the x value into the equation

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Check

1/8x - 1/10x = 1

1/8(40) - 1/10(40) = 1

40/8 - 40/10 = 1

5 - 4 = 1

1 = 1

Answer 2

In 1 hour the inlet pipe fills 1/8 part of the pool
In 1 hour outlet pipe take empty the 1/10 part of the pool

So, in 1 hour the pool gets filled up, (1/8-1/10) = 1/40 part

Now, 1/40 part of the pool gets filled up in 1 hour
So, 1 part or whole pool gets filled up in 1/(1/40) hours = 40 hours

Hope this makes your problem solved for similar ones too. The idea here is to make use of a constant unit, here we used 1 hour time.

Answer 3

In 8 hrs the pool is filled by inlet.
So in 1 hour, inlet fills 1/8 th of the pool.

In 10 hours the pool is emptied by the outlet, so in 1 hour the outlet empties 1/10th of the pool.

If both are on, (1/8 - 1/10) = 1/40 th of the pool is filled in 1 hour
<1/8th is filled, 1/10th is emptied>
So the pool will be filled in 40 hours

Answer 4

Suppose the volume of the pool is a 1000 cubic litres
It takes 8 hours to fill, and fills 1000/8 in an hour

Similarly, it takes 1000/10 to empty

With both the pipes open, it will take 1000/8 less 1000/10, i.e. 125 minus 100 = 25 litres an hour. Now divide 1000 by 25 and you will have the pool full in 40 hours with both the pipes open.

Answer 5

The fill rate is 1 pool filled per 8 hrs or 1/8 & the drain rate is 1 pool drained per 10 hrs or 1/10 it can only be filled by the difference in the 2, i.e. Fill Time = (1/8) - (1/10) = (10 - 8)/80 = 2/80 = 1/40 which means 1 pool filled in 40 hrs.

Answer 6

In 1 hr it fills 1/8 of total volume of pool
In 1 hr it empties 1/10 of total volume of pool.
If both lets are opened at same time., then
In 1 hr it fills 1/8-1/10 of the total volume of pool
=1/8-1/10 (solve this )
= 1/40 of the total volume of pool
Therefore it takes 40 hrs to fill the pool

Answer 7

Alright,

First we'll find the rate of flow of water through these pipes.

The inlet pipe is bigger and takes 8 hrs to fill the pool.
Then it fills 1/8th of pool in 1 hour.

The outlet is smaller and lets out the entire pool in 10 hours.
So, it lets out 1/10th of the pool in 1 hour.

Hence effectively, the rate of flow into the pool is 1/8 - 1/10 per hour.

=> (10 - 8)/ 80 = 2/80 = 1/40.

Hence it takes 40 hours to fill the pool.

Hope its right.

Answer 8

in one hr:1/8 of the volume can be filled and 1/10 of the volume can be emptied.
1/8-1/10=5/40-4/40=1/40
so in one hr1/40 of the pool can be filled.the whole volume will filled in 40 hrs.

Answer 9

Let the volume = x
8 hrs to fill means x/8 per hr
10 hr to discharge means x/10 per hr.
Balance in tank per hr = x/8 - x/10 = x/40
If x/40 or (1/40)x remains in tank per hr
Then x will take 40hrs.

Answer 10

permit A = Justin's age now permit A+10 = Jeremiah's age now in 5 years, A+5 = Justin's age A+10+5 = A+15 = Jeremiah's age yet in accordance to the given subject, Jeremiah's age would be two times Justin's age for this reason we could have the equation: A + 15 = 2 x (A+5) A + 15 = 2A + 10 15 - 10 = 2A - A A = 5 Justin's age now : A = 5 yrs old Jeremiah's age now: A+10 = 15 yrs old