Answer: With 11 pipes, you need 31.82 minutes to fill the tank.
Step-by-step explanation:
Let's define R as the rate at which one single pipe can fill a tank.
We know that 7 of them can fill a tank in 50 minutes, then we have the equation:
7*R*50min = 1 tank
Whit this equation, we can find the value of R:
R = 1 tank/(7*50min) = (1/350) tank/min.
Now that we know the value of R, we can do the same calculation but now with 11 pipes.
Then the time needed to fill the tank, T, is such that:
11*(1/350 tank/min)*T = 1 tank
We need to isolate T.
T = 1 tank/(11*(1/350 tank/min)) = 31.82 min
With 11 pipes, you need 31.82 minutes to fill the tank.
From the given question we come to know of certain number of facts and they are:
At 1:00 PM the water level of the pond was = 13 inches
At 1:30 PM the water level of the pond was = 18 inches
At 2:30 PM the water level of the pond was = 28 inches
From the above given facts we can easily find the amount of water changing every half an hour.
Amount of increase in water from 1:00PM to 1:30 PM = (18 - 13) inches
= 5 inches
Amount of increase in water level from 1:30PM to 2:30PM = (28 -18) inches
= 10 inches
From the above two deductions we can come to the conclusion the the constant rate of change in water level is 5 inches for every half an hour.
260 was its original prize.
Answer:1331cm
Step-by-step explanation:vol=lbh
11*11*11cm=1331cm