Tony needs to pick up his sister at 5:20 PM. The drive takes 40 minutes. We need to determine what time Tony should leave.

1. Problem Description

Tony needs to pick up his sister at 5:20 PM. The drive takes 40 minutes. We need to determine what time Tony should leave.

2. Solution Steps

To find the time Tony should leave, we need to subtract the travel time (40 minutes) from the arrival time (5:20 PM).

First, write down the arrival time.

Arrival time: 5:20 PM

Then, subtract 40 minutes from 5:20 PM:

$5:20 \text{ PM} - 40 \text{ minutes}$

Since 20 is less than 40, we need to borrow an hour from the 5 hours. One hour is equal to 60 minutes.

So we have:

$4 \text{ hours} + 60 \text{ minutes} + 20 \text{ minutes} - 40 \text{ minutes}$

$4 \text{ hours} + 80 \text{ minutes} - 40 \text{ minutes}$

$4 \text{ hours} + 40 \text{ minutes}$

Therefore, the time Tony should leave is 4:40 PM.

3. Final Answer

4:40 PM