Playing With Numbers

In a morning walk, three persons step off together. Their steps
measure 80 cm, 85 cm and 90 cm respectively. What is the minimum distance
each should walk so that all can cover the same distance in complete steps?

Two tankers contain 850 litres and 680 litres of kerosene oil
respectively. Find the maximum capacity of a container which can measure the
kerosene oil of both the tankers when used an exact number of times.

Find the LCM of 20, 25 and 30.

Find the LCM of 40, 48 and 45.

Find the LCM of 24 and 90.

Find the LCM of 12 and 18.

Find the prime factorisation of 980.

Find the common multiples of 3, 4 and 9.

Find the common factors of 75, 60 and 210.

Write all the prime numbers less than 15.

Write first five multiples of 6.

Find the factors of 36.

Write all the factors of 68.