Question

find the greatest four digit number which is divisible by 15, 20 and 25

Answer 1

since the greatest 4 digit no=9999
Now,
the LCM OF(15,20,25)=300
DIVIDING 9999 BY 300
300)9999(33
900
____
990
900
_____
90
Q=33
R=90
So,if we subtract 90 from 9999 then 300 can divide it completely
So,9999-90=9900
So,9900 is the no divided by 15,20,25

Answer 2

9900 is the largest 4 digit number divisible by 15,20,25