Find the greatest number that will divide 390, 495 and 300 without leaving a remainder. 

There are 24 peaches, 36 apricots and 60 bananas and they have to be arranged in several rows in such a way that every row contains the same number of fruits of only one type. What is the minimum number of rows required for this to happen? 

A fraction becomes $${1\over 6}$$ when 4 is subtracted from its numerator and 1 is added to its denominator. If 2 and 1 are respectively added to its numerator and the denominator, it becomes $${1\over 3}$$. Then, the LCM of the numerator and denominator of the fraction, must be 

A farmer has 945 cows and 2475 sheep. He farms them into flocks, keeping cows and sheep separate and having the same number of animals in each flock. If these flocks are as large as possible, then the maximum number of animals in each flock and total number of flocks required for the purpose are respectively 

Three bells ring simultaneously at 11 a.m. They ring at regular intervals of 20 minutes, 30 minutes, 40 minutes respectively. The time when all the three rings together next is:

The LCM of three different numbers is 120. Which of the following cannot be their HCF? 

Two numbers are in the ratio 3 : 4. Their L.C.M. is 84. The greater number is 

The HCF and LCM of two numbers are 12 and 924 respectively. Then the number of such pairs is: