If the difference between CI and SI for 3 years at the rate of 10% is Rs 31. Find the principle.

Which of the following is linear equation.

Two pipes A and B can fill a tank in 3 hours and 5 hours. Then, if all three are open, the tank is filled in 30 hours. Find in how many hours a third pipe will empty the tank?

A boat goes from A to B in upstream and come back from B to A downstream taking a total time of 3.5 hours. If the speed of boat in still water is 7 km/hr and the speed of stream is 5 km/hr. Find the distance between A and B. 

Directions: Each of the questions consists of a question followed by three statements. You have to study the questions and the statements and decide which of the statements(s) is/are necessary to answer the question. 

What is the speed of the train?
 I. The train crosses a signal pole in 13 sec.
 II. The train crosses a platform of length 250 m in 27 seconds.
 III. The train crosses another train running in the same direction in 32 seconds.

The monthly income of a person was ₹ 13,500 and his monthly expenditure was ₹ 9,000. Next year his income increased by 14% and his expenditure increased by 7%. The per cent increase in his savings was  

In the following frequency table, the value of H will be

The average of three numbers is 40. The first number is twice the second and the second one is thrice the third number. The difference between the largest and the smallest numbers is