A and B together can complete a work in 12 days, A alone can complete in 20 days. If B now does the work only for half a day daily, then the number of days required to complete the work, by A and B together, is

The greatest fraction out of $$ {2\over 5},{5\over 6},{11\over 12},and \ {7\over8}$$ is

The diameter of a roller is 84 cm and its length is 120 cm. It makes 500 complete revolutions to move once over to level a playground. Find the area of the playground.

How many times the keys of a typewriter have to be pressed in order to write number from 121 to 1346?

If the population of a town is 64000 and its annual increase is 10%, then its population at the end of 3 yeas will be :

The sum of the HCF and LCM of two numbers is 680 and the LCM is 84 times the HCF. If one of the numbers is 56, the other is : 

Three men step off together from the same spot. Their steps measure 63 cm, 70 cm and 77 cm respectively. The minimum distance each should cover so that all can cover the distance in complete steps is 

The product of two numbers is 45 and their difference is 4. The sum of squares of the two numbers is