Adrian exercised three days during the past week. He exercised for 100 minutes and 20 seconds on the first day, 96 minutes and 25 seconds on the second day, and 103 minutes and 15 seconds on the third day.

How many hours did he spend exercising during the week?

[tex]
\[
\begin{aligned}
& \text{Units of Time} \\
60 \text{ seconds (sec)} & = 1 \text{ minute (min)} \\
60 \text{ minutes} & = 1 \text{ hour (hr)} \\
24 \text{ hours} & = 1 \text{ day} \\
7 \text{ days} & = 1 \text{ week} \\
\end{aligned}
\]
[/tex]

To find out how many hours Adrian spent exercising during the week, we need to add up the time he spent on each of the three days, and then convert that total time into hours. Let's go through this step by step.

1. Convert each day's exercise time into seconds:

- First Day: Adrian exercised for 100 minutes and 20 seconds.
- Convert the minutes to seconds: [tex]$100 \times 60 = 6000$[/tex] seconds.
- Add the remaining 20 seconds: [tex]$6000 + 20 = 6020$[/tex] seconds.

- Second Day: Adrian exercised for 96 minutes and 25 seconds.
- Convert the minutes to seconds: [tex]$96 \times 60 = 5760$[/tex] seconds.
- Add the remaining 25 seconds: [tex]$5760 + 25 = 5785$[/tex] seconds.

- Third Day: Adrian exercised for 103 minutes and 15 seconds.
- Convert the minutes to seconds: [tex]$103 \times 60 = 6180$[/tex] seconds.
- Add the remaining 15 seconds: [tex]$6180 + 15 = 6195$[/tex] seconds.

2. Add up the total seconds from all three days:

- Total seconds = [tex]$6020 + 5785 + 6195 = 18000$[/tex] seconds.

3. Convert the total seconds to hours:

- There are 3600 seconds in an hour. So, divide the total seconds by 3600 to convert to hours:
- Total hours = [tex]$18000 \div 3600 = 5$[/tex] hours.

Thus, Adrian spent a total of 5 hours exercising during the week.