A group of 5 girls booked a computer for 2 hours. They took turns to work on the computer for their project. At any time, only 3 girls worked on the computer. On average, how long did each girl work on the computer? Give your answer in hours and minutes.

1. Calculate the total computer time available

Since 3 girls are working on the computer at any one time for 2 hours, the total computer time available is $3 \times 2 = 6$ hours.

2. Calculate the average time each girl worked

The total computer time is shared equally among the 5 girls.
Average time per girl = $\frac{6}{5} = 1.2$ hours.

3. Convert the time into hours and minutes

$1.2$ hours = $1$ hour and $0.2 \times 60$ minutes = $1$ hour $12$ minutes.