Question

Find the number nearest to 110000 but greater than 100000 which is exactly divisible by each of 8,15 and 21

Answer 1

lcm of 8,15,21=840
multiply 840 that is nearest to 110000
that is 130
hence 840 *130 =109200

Answer 2

LCM of 8 = 2 * 2 * 2

LCM of 15 = 3 * 5

LCM of 21 = 3 * 7


LCM of 8,15,21 = 2^3 * 3 * 5 * 7

                         = 840.


Division Method:

840)110000(130
        840
        ----------
          2600
          2520
        -----------
             800
        ------------



Therefore the number nearest to 110000 but greater than 100000 that is divisible by 840 is 110000 - 800 = 109200.


The required number is 109200.


Hope this helps!