Answer:
984 adults
281 teens
492 children
Step-by-step explanation: Multiply the total by the corresponding percentage to find the number. We assume the percentages have been rounded, so some adjustment is needed in the result of the multiplication.
{adults, teens, children} = 1757 × {.56, .16, .28} = {983.92, 281.12, 491.96}
≈ {984, 281, 492}