Jonathan can type a 20 page document in 40 minutes, Susan can type it in 30 minutes, and Jack can type it in 24 minutes. Working together, how much time will it take them to type the same document?

One of the factor (8^2k+5^2k) where k = odd , find the value of k?

What is the reminder when {(127^97)+(97^97)} is devisible by 32

The sum of two co prime number is 945 the find their LCM.

Find the least prefect square number which completely divisible by 56, 60, 84 and 96 ?

Let X be the least number divisible by 16, 24, 30, 36 and 45  and X is also a perfect square .what  is the reminder when X is divisible by 123 .

The greatest number of 5 digit that exactly divisible by each 8,12,15 and 20.

The least number of 5 digit which exactly divisible by 52, 56, 78 and 91.

The number between 22000 and 23000 that divisible by each of 12,18,21 and 32

The greatest number of six digit which gives reminder 10, when divisible by 36, 48, 54, 60 and 90