Question

If the function b(t)
gives the number of boats it takes
people to cross a river, what is the appropriate domain?

Note: Assume that each boat carries the same number of people.

Responses
A integersintegers
B natural numbersnatural numbers
C real numbersreal numbers
D whole numberswhole numbers

Answer 1

B — natural numbers.

Reason: the input is a count of people, which must be a counting (positive integer) value (no fractions or negatives). (If you allow 0 people, some would use "whole numbers" instead.)