Question

find the greatest four digit number that is exactly divisible by 9 ,12 and 15​

Answer 1

Answer:

First find LCM which is 180

Now

$180k \leqslant 9999 \\ k \leqslant \frac{9999}{180} \\ k \leqslant 55.50$

So k = 55

and number will be

$180k = 180 \times 55 = 9900$

Answer 2

Answer:

by 12,15=9720 and by 9=9999 by taking out lcm