Find the largest number of 4-digits divisible by 12, 15 and 18.

Question: Find the largest number of 4-digits divisible by 12, 15 and 18.Solution:Required largest number must be divisible by the L.C.M. of 12, 15 and 18L.C.M. of 12, 15 and 1812 = 2 × 2 × 315 =5 × 318 = 2 × 3 × 3L.C.M. = 180Now divide 9999 by 180, we get remainder as 99The required largest number = (9999 - 99) = 9900Number 9900 is exactly divisible by 180.