In the middle of around pool lies a water-lily . The water-lily doubles in size every day . After exactly 20 days the complete pool will be covered by the lily. After how days will half of the pool be covered by water-lily ?

How many of the integers between 110 and 120 are prime numbers ?

Unless the new reserves are found soon, the world's supply of coal is being depleted in such a way that with d...

From a group of 7 men and 6 women, five persons are to be selected to from a committee so that at least 3 men...

What is the missing number in the following series ? 1, 4, 9, ?, 25

A train which travels at a uniform speed due to some mechanical fault after traveling for an hour goes at 3/5t...

M goes to the gym every fourth day . E's exercise routine is to go every third day. Today is Monday and both M...