LCM HCF

What is the highest 3 digit number which is exactly divisible by 3, 5, 6 and 7?

Solution

The least number which is exactly divisible by 3, 5, 6, & 7 is LCM(3, 5, 6, 7) = 210.

So, all the multiples of 210 will be exactly divisible by 3, 5, 6 and 7.

Thus, such greatest 3 digit number is 840 (210 × 4).