To find out the amount to be divided just add the ratios together: 15.
Actually, the more general answer is 15n where n is a positive integer, if the divided amounts are to be whole numbers. The minimum is 15 (whether it's 15c, $15 or 15 candies).
That means the divided amounts are 5, 4, 3, 2, 1, all whole numbers. But you could also have 10, 8, 6, 4, 2 (for amount 30, n=2), and so on. In general, you would have 5n, 4n, 3n, 2n, n. Example: n=4 gives you amount=60 and 20, 16, 12, 8, 4 are the divided amounts. As it happens, 60 is also the LCM of 1, 2, 3, 4, 5 but the amount is not required to be the LCM.