If 2x-y=4 then 6x-3y=?

If x=y=2z and xyz=256 then what is the value of x?

(1/10)18 - (1/10)20 = ?

Pipe A can fill in 20 minutes and Pipe B in 30 mins and Pipe C can empty the same in 40 mins.If all of them work together, find the time taken to fill the tank

Thirty men take 20 days to complete a job working 9 hours a day. How many hour a day should 40 men work to complete the job?

Find the smallest number in a GP whose sum is 38 and product 1728

A boat travels 20 kms upstream in 6 hrs and 18 kms downstream in 4 hrs. Find the speed of the boat in still water and the speed of the water current?

What is the missing number in this series?
8 2 14 6 11 ? 14 6 18 12