Mathematics Question and Answer for Exams

A Cistern can be filled by a tap in 4 hours while it can be emptied by another tap in 9 hours. If both the taps are opened simultaneously then after how much time will the cistern get filled?

Two pipes A and B can fill a tank in 3 hours and 5 hours. Then, if all three are open, the tank is filled in 30 hours. Find in how many hours a third pipe will empty the tank?

If the square root of 841 is 29, then 0.00000841 is equal to :

The sum of the squares of 3 consecutive positive numbers is 365. The sum of the numbers is

A man can swim at the rate of 3 km/hr. in still water. Then, if speed of the stream is 2 km/hr., then in what time he will cover a total distance of 5 km in with the stream and against the stream?

A boat running upstream takes 7 hours and 40 minutes to cover a certain distance while it takes 5 hours to cover the same distance downstream. What is the ratio between the speed of the current and speed of the boat respectively? 

LCM of two numbers is 2079 and their HCF is 27. If one of the numbers is 189, the other number is

a and b are two whole numbers and c is their HCF, then the LCM of those two numbers is

If the numerator of a fraction is increased by 250% and the denominator is increased by 400%. The resultant fraction is7/19 . What is the original fraction?

Let p, q and r be the fraction such that p<q<r. If r is divided by p, the result is 5/2, which exceeds q by 7/4. If $$p+q+r=1{11\over12} $$ then what is the value of (r-p)?