Two pipes

How long will the pool be filled with a double supply pipe if it takes the pool to fill the first pipe by 4 hours longer and the second pipe 9 hours longer than both pipes open at the same time?

Correct result:

t =  6 h

Solution:

$$\begin{gathered} t_1=t+4 \\ {t}_2=t+9 \\ t\cdot ({\displaystyle \frac{1}{t_1}}+{\displaystyle \frac{1}{t_2}})=1 \\ t\cdot ({\displaystyle \frac{1}{t+4}}+{\displaystyle \frac{1}{t+9}})=1 \\ t\cdot (t+9)+t\cdot (t+4)=(t+9)\cdot (t+4) \\ {t}^2=36 \\ t>0 \\ t=\sqrt{36}=6\text{ h} \end{gathered}$$

Try another example

Showing 0 comments:

Next similar math problems:

• Pool
  If water flows into the pool by two inlets, fill the whole for 19 hours. The first inlet filled pool 5 hour longer than the second. How long pool take to fill with two inlets separately?
• Oil tank and pipes
  The underground oil tank can be filled by two oil pipelines. The first is filled in 72 hours and the second in 48 hours. How many hours from the moment when first pipeline began to fill the oil is it necessary to start filling it with the second to fill i
• Two workers
  Two workers should fulfill certain task together for 5 days. If the first worker increased their performance twice and second twice fell, it took them just four days. For how many days would handle the entire task first worker himself?
• Inlet minus outlet
  Water flows into the tank through two pipes and flows out of the third pipe spontaneously. The pipe A itself would fill the tank in 3 hours, the pipe B itself would fille in 4 hours, and the pipe C itself would flow out in 12 hours. How long will the tank
• Two cars
  Two cars started against each other at the same time to journey long 346 km. The first car went 53 km/h and the second 53 km/h. What distance will be between these cars 20 minutes before meet?
• Three pumps
  We are filling the pool. The first pump would be filled in 12 hours, the second pump in 15 hours. If all three pumps were running at the same time, it would fill the pool for 4 hours. How long would the pool fill only with the third pump?
• Right triangle
  Legs of the right triangle are in the ratio a:b = 2:8. The hypotenuse has a length of 87 cm. Calculate the perimeter and area of the triangle.
• ICE train
  German runways test a new ICE train between Munich and Berlin. The train runs to Berlin at a slow speed of 100 km/h. Back from Berlin goes faster. How quickly did the train have to go on a return trip so that the total average train speed for both journey
• Rectangular cuboid
  The rectangular cuboid has a surface area 5334 cm², its dimensions are in the ratio 2:4:5. Find the volume of this rectangular cuboid.
• Secret treasure
  Scouts have a tent in the shape of a regular quadrilateral pyramid with a side of the base 4 m and a height of 3 m. Determine the radius r (and height h) of the container so that they can hide the largest possible treasure.
• Two trucks
  Two trucks left cities A and B against each other and met after an hour. The first car came to B 27 minutes later than the second car to A. Calculate the car speed if the distance between cities A, B is 90 km.
• Direct route
  From two different places A and B connected by a direct route, Adam (from city A) and Bohus (from city B) started at a constant speed. As Adam continued to go from A to B, Bohus turned around at the time of their meeting and at the same speed he returned
• Four integers
  Fnd four consecutive integers so that the product of the first two is 70 times smaller than the product of the next two.
• Square vs rectangle
  Square and rectangle have the same area contents. The length of the rectangle is 9 greater and width 6 less than side of the square. Calculate the side of a square.
• Uboid volume
  Calculate the cuboid volume if the walls are 30cm², 35cm², 42cm²
• Trapezoid
  Area of trapezoid is 135 cm². Sides a, c and height h are in a ratio 6:4:3. How long are a,c and h? Make calculation...
• Rectangle diagonals
  It is given rectangle with area 24 cm² a circumference 20 cm. The length of one side is 2 cm larger than length of second side. Calculate the length of the diagonal. Length and width are yet expressed in natural numbers.