30 pens and 75 pencils altogether were purchased for Rs .510. If the average price of a pencil was Rs. 2, what was the average price of a pen? 

The population of Jaipur is 20,00,000. If it is increased by 5 %, 10%, 20% respectively in the next three years, then find the population of Jaipur after 3 years.

A train after travelling 150 Km. meets with an accident and then proceeds with 3/5 of its former speed and arrives at its destination 8 hours late. Had the accident occurred 360 Km. farther, it would have reached the destination 4 hours late. What is the total distance travelled by the train?

If the angles of a triangle are in the ratio of 1:4:7, then find the ratio of the greatest angle to the smallest angle.

Two numbers are in the ratio of 3: 5. If 9 be subtracted from each, then they are in the ratio of 12: 23. Find the numbers. 

A contract is to be completed in 50 days and 105 men were set to work, each working 8 hour a day. After 25 days, 2/5th of the work is finished. How many additional men be employed, so that the work may be completed on time, each man now working 9 hour a day?

A bag contains 2 red, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?

The price of 6 pencils is Rs. 30 and that of 12 pens is Rs. 120. What is the average price of 50 pencils and 50 pens?