Final answer:
The domain is t ≥ 0 and the range is 0 ≤ m ≤ 500.
Step-by-step explanation:
The given set of ordered pairs (t, m) represents the remaining mass of a radioactive substance that has been decaying for t hours. The domain of this set is the range of values that t can take, which can be any non-negative real number since time cannot be negative. So, the domain is t ≥ 0.
The range of this set is the range of values that m can take, which represents the remaining mass. Since the substance is decaying, the remaining mass cannot exceed the initial mass or be negative. Thus, the range is 0 ≤ m ≤ 500.