Solve the following word problem. A fish is swimming at −10.8

Question

meters, or 10.8 meters below sea level. Every 2 minutes it descends another 1.5 meters. How long will it take for the fish to reach a depth of −37.8
meters? Show your work and write a sentence to explain what your answer means.
7th grade 3 sentences

Answer 1

To find out how long it will take for the fish to reach a depth of -37.8 meters, we start by calculating the difference between its starting depth and the target depth:

1. Calculate the difference in depth: \[ -37.8 \text{ meters} - (-10.8 \text{ meters}) = -37.8 + 10.8 = -27 \text{ meters} \]

2. Determine how many meters the fish descends every 2 minutes: The fish descends 1.5 meters every 2 minutes.

3. Calculate the time it takes to descend 27 meters: \[ \text{Number of 2-minute intervals} = \frac{27 \text{ meters}}{1.5 \text{ meters}} = 18 \text{ intervals} \] \[ \text{Total time} = 18 \text{ intervals} \times 2 \text{ minutes/interval} = 36 \text{ minutes} \]

In conclusion, it will take the fish 36 minutes to reach a depth of -37.8 meters. This means that after 36 minutes of swimming downwards, the fish will be at a depth of 37.8 meters below sea level.