If the cost of 1 dozen apples is Rs. 18, then the cost of 25 apples will be -

At a construction site, 200 workers were working on a building which is scheduled to end within 250 days. After 30 days, 20 workers leave the job. How many more days will it take to complete the work? 

If A:B :: 6:11 and B:C :: 6:7, then A:C ::_____

A train covers 400 m distance in 24 sec. Its speed is-

The salary of a person is increased by 20%. By what % the new salary must be reduced to restore the original salary?

The diameters of two cones are equal. If their slant heights are in the ratio 5: 2, then the ratio of curved surface areas of the cones is _________ .

In a school, if there are 36% boys and 352 girls, then the number of boys is ________.

For any real value of $${\sqrt {secθ-1}\over \sqrt {secθ+1} }=?$$