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

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:

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:

An item is marked for sale at ₹7,200. A dealer allows a discount of 10% and yet makes a profit of 8%. What would have been his gain percentage, if no discount was allowed?

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'?

Vinay saves 10% of his income. If his income increases by 16%, and his saving increases by 10%, then what percentage does his expenditure increase?

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.

There are 48 students in a college union and the ratio of the number of boys to the number of girls is 5:3. The number of girls to be included in this union, so that the ratio of the number of boys to number of girls become 6:5, is:

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?