Two pipes 'A' and 'B' can fill a water tank in 30 minutes and 20 minutes, respectively. Initially pipe 'A' was opened and after 5 minutes, pipe 'B' was also opened. Find the total time (in minutes) taken by the pipes to fill the tank.

Two trains 'A' and 'B' started running at the same time. Train 'A' takes 3 hours more than train 'B' to cover 540 km. But if train 'A' doubles its speed, it covers 540 km in 1½ hours less than train 'B'. What is the speed (in km/h) of train 'B'?

Four years ago, the ages of Rekha and her mother were in the ratio 1:6. Five years hence, the ratio will become 1:3. How old will the mother be after 10 years from now?

A car covers a distance of 75 km at a speed of 60 km/hr. It covers the next 5 km at a speed of 12 km/hr and the last 40 km at a speed of 36 km/hr. The average speed of the car during the entire journey (in km/hr) is:

The length of a hall is 22 m and the width is 18 m. If the sum of the areas of the floor and the roof is equal to the total area of the four walls, then what is the volume of the hall?

The average of 11 consecutive even numbers written in ascending order is 30. What is the average of the 3rd and the 10th number?

Inside a rectangular park of dimensions 100m × 80m, walking paths 3m wide are to be constructed as shown in the figure given below (a 3 m path along the inside of the boundary, plus one path parallel to the length and one parallel to the width crossing in the middle). Find the co…

A sum of money invested at a certain rate of simple interest amounts to ₹7400 in 6 years and to ₹8200 in 8 years. The rate of interest per annum, is:

The co-ordinates of midpoints of the sides AB, BC, and CA of a triangle ABC are (3, 6), (5, 3), and (8, 5) respectively. The co-ordinates of vertex A are: