Question
Pipe ‘A’ and pipe ‘B’ can fill a cistern in 20
minutes and 10 minutes respectively. Pipe ‘C’ alone can empty the cistern in 12 minutes. If all three pipes are opened together then what is the time taken to fill 50% of the cistern?Solution
Let the capacity of the cistern = 60 units Then, efficiency of pipe ‘A’ = 60/20 = 3 units/minute Efficiency of pipe ‘B’ = 60/10 = 6 units/minute Efficiency of pipe ‘C’ = 60/12 = 5 units/minute So, combined efficiency of pipes ‘A’, ‘B’ and ‘C’ = 3 + 6 – 5 = 4 units/minute 50% of the cistern’s capacity = 30 units Therefore, time taken by all 3 pipes together to fill 50% of the cistern = 30/4 = 7.5 minutes
The volume of a cube is 64 cm³. If the cost of painting the cube is Rs. 15 per cm², then find the cost of painting five faces of the cube.
How many bullets can be made out of a lead cylinder 32cm high and 12 cm radius, each bullet being 4 cm in diameter?
Find the area of the triangle ABC. Where AC=17cm, AB=15cm, BC=8cm
The breadth of a rectangle is increased by 5 cm, it will become twice the length of the rectangle. If the new perimeter is 330 cm, then find the origina...
The ratio between the length and the breadth of a rectangular park is 3 : 2. If a man cycling along the boundary of the park at the speed of 12 km/hour...
In triangle ABC, AD is the angle bisector of angle A. If AB = 8.4 cm and AC = 5.6 cm and DC = 2.8 cm, then the length of side BC will be:
A sum of Rs. 21500 was lent partly at 4% p.a. and remaining at 6% p.a. simple interest. The total interest received after 3(1/2) years is Rs. 3521. The ...
Two sides of the triangle are 14.8 cm and 10 cm. If height of the triangle corresponding to 14.8 cm side is 8 cm, find the area?
...The curved surface area of a hemisphere is 72π cm2, then its radius is:
Relevant for Exams:
