The sum of three

Three consecutive multiples of 8 means, three consecutive numbers that are divisible by 8.
Let the three consecutive multiples of 8 are
= 8(x - 1), 8x, 8(x + 1)
= 8 x - 8, 8 x, 8 x + 8

Then,
Sum of three consecutive multiples of 8 = 888
8 x - 8 + 8 x + 8 x + 8 = 888

24 x = 888

Now, 
8(x - 1) = 8(37 - 1) = 8(36) = 288
8x = 8(37) = 296
8(x + 1) = 8(37 + 1) = 8(38) = 304

Therefore, the numbers are, 288,296 and 304.