An emergency team needs to be on the roof of the hospital 3 minutes before the helicopter arrives. It takes the team 4 minutes to reach the roof. At what time should the team start moving to the roof to meet the helicopter? Explain your reasoning
3+4=7 minutes before the chopper lands.
To determine the time the team should start moving to the roof to meet the helicopter, we'll need to consider the time it takes for the team to reach the roof and the additional 3 minutes they need to be there before the helicopter arrives.
Let's say the helicopter is scheduled to arrive at time "X".
The team takes 4 minutes to reach the roof. So, they should start moving at X - 4 minutes to reach the roof by the time the helicopter arrives.
However, they also need to be on the roof 3 minutes before the helicopter arrives. So, they should start moving to the roof 3 minutes earlier than X - 4.
Therefore, the team should start moving to the roof at (X - 4) - 3 minutes, which simplifies to X - 7 minutes. This means they should start moving 7 minutes before the scheduled arrival time of the helicopter to meet it on time.
For example, if the helicopter is scheduled to arrive at 2:00 PM, the team should start moving to the roof at 1:53 PM, which is 7 minutes before the scheduled arrival time.