A tank of 30 meter long, 20metre wide and 12 meter deep is dug in a rectangular field of length 588 meter and breadth 50 meter. The earth sand so dug out is spread evenly on the remaining part of the field. The height of the field raised by it is

Oranges are bought at 7 for Rs. 3. At what rate per hundred must they be sold to gain 33 % ? 

If the length of a shadow of a pole on a level ground is twice the length of that pole, the angle of elevation of the sun is:-

By a selling basket for Rs. 19.50, a shopkeeper gains 30 %. For how much should he sell it to gain 40 %? 

Rohit purchased 12 kg of oranges for a total price of ₹480 and 18 kg of guavas at 30 per kg. What cost of the fruits purchased by Rohit?

In a bag there are 4 white, 4 red and 2 green boxes. Two boxes are drawn at random. What is the probability that at least one boxes is of red colour?

In a school with 600 students the average age of the boys is 12 years and that of the girl is 11 years. If he average age of the students is 11 years 9 months, then the number of girls in the school is