Answer:
40 seconds
Step-by-step explanation:
The ratio would be 3:120, indicating the amount of times it went up for air in 120 seconds. In order to find the answer, we'll find the unit rate. 120 divided by 3 is evenly 40. That means, the unit rate is 1:40. It also means that 40 seconds went by before the manatee surfaced the first time (if it held its breath for the same rate).
