Answer:
173
Step-by-step explanation:
Assume the natural number is x.
x/12 = ... R 5
x/15 = ... R 8
x/18 = ... R 11
Thus, x+7 is divisible by 12, 15 and 18 all together.
The smallest possible number of x+7 can be calculated with prime factorization.
12=2^2 * 3
15=3 * 5
18=2 * 3^2
The smallest possible number for x+7 is 2^2 * 3^2 * 5 = 4 * 9 * 5 = 180.
Therefore, the smallest possible solution for x is 180 - 7 = 173.
