The HCF of two numbers is 21 and their LCM is 840. If one of the numbers is 49, then the other number is:

If the LCM of two numbers is 288 and their ratio is 4 : 9, then HCF of the numbers is : 

Find the LCM and HCF of 27 and 81.

The LCM of 1.2 and 2.7 is:

By what least number should 21600 be multiplied to make it a perfect square?

Two pipes of length 1.5 m and 1.2 m are to be cut into equal pieces without leaving any extra length of pipes. The greatest length of the pipe pieces of same size which can be cut from these two lengths will be

The sum of two and the product of 23 is 120. The sum of the areas will be:

The greatest common factor of two co-prime numbers will be