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

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

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

Which of the following numbers is divisible by 11?

The HCF of two numbers is 24. If sum of the numbers is 480, how many such pairs of numbers are possible?

Find the LCM of the fractions $${2\over 5}$$, $${3\over 7}$$ and $${4\over 9}$$

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

The LCM of four consecutive numbers is 60 The sum of the first two numbers is equal to the fourth number. What is the sum of four numbers?