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?
Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):
Showing 0 comments:
Be the first to comment!
To solve this example are needed these knowledge from mathematics:
Next similar examples:
Three-quarters of boats are white, 1/7 are blue and 9 are red. How many boats do we have?
- Two friends
Peter can do all his work himself in 6 hours. Martin can do the same work himself in 8 hours. Peter worked first and then replaced by Martin. Whole work was done in 6.5 hours. Calculate how long Peter worked before replaced by Martin.
- Area to volume
If the surface area of a cube is 486, find its volume.
- Substitution method
Solve goniometric equation: sin4 θ - 1/cos2 θ=cos2 θ - 2
- Non linear eqs
Solve the system of non-linear equations: 3x2-3x-y=-2 -6x2-x-y=-7
- Cube diagonals
Calculate the length of the side and the diagonals of the cube with a volume of 27 cm3.
- Rectangle 45
The perimeter of a rectangle is 60cm. If the length of the rectangle is 20cm. a)find the width b)find the area.
- Diamond diagonals
Find the diamond diagonal's lengths if the area is 156 cm2 and side is 13 cm long.
- Marriage sttus
In our city, there are 3/5 of the women married to 2/3 of the men. Find what part of the population is free.
- Calculate 2
Calculate the largest angle of the triangle whose side are 5.2cm, 3.6cm, and 2.1cm
The sum of all cube edges is 30cm. Find the surface area of the cube.
- Diagonals of a rhombus 2
One diagonal of a rhombus is greater than other by 4 cm . If the area of the rhombus is 96 cm2, find the side of the rhombus.
How high is the airplane's pilot to see 0.001 of Earth's surface?
- Diagonals of the rhombus
How long are the diagonals e, f in the diamond, if its side is 5 cm long and its area is 20 cm2?
- Isosceles trapezium
Calculate the area of an isosceles trapezium ABCD if a = 10cm, b = 5cm, c = 4cm.
- Cylinder height
Calculate the height of the cylinder and its surface is 2500 dm2 and the bases have a diameter 5dm.
- Symmetry by plane
Determine the coordinates of a image of point A (3, -4, -6) at a symmetry that is determined by the plane x-y-4z-13 = 0