A racing car going at an average speed of 108 km/ hr takes 15 minutes to complete a lap on a racing track. By how much should it increase its speed (in km/hr) to complete the lap in 12 minutes?

Direction: Study the double bar graph given below and answer the questions.

The average of the number of students participating in cultural events is:

By selling 15 mangoes, a fruit seller gains the selling price of 3 mangoes. His gain is

One fill pipe A takes 3 minutes more to fill the cistern than two fill pipes A and B opened together to fill it. Second fill pipe B takes $$ {21{1\over 3}}$$ minutes more to fill cistern than two fill pipes A and B opened together to fill it. When will the cistern be full if both pipes are opened simultaneously?

If P= 2² + 6² + 10² +14² +……..94² and Q=1² + 5² + 9² +……..81², then what is the value of P- Q ?

Find compound interest on Rs. 50000 at 12 % per annum for 6 months, compounded quarterly. 

What approximate value should come in place of the question mark(?) in the following question?
105.003+307.993+ 215.630=?

In how many different ways can the letters of the word 'NATIONAL' be arranged?