If selling price is doubled, the profit triples, Find the profit percent,

The average weight of 8 persons increases by 2.5 kg when a new person comes in place of one of them weighing 6...

3 pumps , working 8 hours a day, can empty a tank in 2 days. How many hours a day must 4 pumps work to empty t...

Running at the same constant rate 6 identical machines can produce a total of 270 bottles per minute . At this...

what least number must be added to 1056 , so that the sum is completely divisible by 23?

Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. what is the probability that the t...

A collection of books went on sale and 2/3 of these were sold for Tk. 2.30 each. None of the 36 remaining book...