Question

Find the greatest five digit number which is exactly divisible by 9,12,15,18

Answer 1

$\bf\huge{99900}$

We are given to find the Largest 5-digit no. divisible by 9, 12, 15 and 18.

To do so, we need to calculate their $\bf{LCM.}$ Any number divisible by LCM will automatically be divisible by them.

When you'll do the calculations you'll get your answer which is 1$\bf{80.}$

Now, In order to get largest 5-digit number divisible by 180 we'll divide largest 5-digit number$\bf{(\:i.e\:99999)}$ by 180.

Then, we'll $\bf{subtract\:the\:remainder}$ from 99999 and the answer we'll get would be divisible by 9, 12, 15 and 18.

After doing the division, you'll get remainder as 99.

So, 99999-99 = 99900

Hence, the greatest number divisible by 9, 12, 15 and 18 is 99900.