Given:
An elf makes 15 present in 1 hour and 30 minutes, that is 90 minutes.
The time taken to make one present by the elf is,
[tex]\begin{gathered} \text{Time for one present =}\frac{90\text{ min}}{15} \\ =6\text{minutes} \end{gathered}[/tex]The time taken to make 8 presnt is,
[tex]\begin{gathered} \text{Time taken for 8 present=8}\times(Timetaken\text{ for one present)} \\ =8\times6 \\ =48\text{ minuts} \\ =\frac{48}{60}\text{ hour} \\ =0.8\text{ hour} \end{gathered}[/tex]Thus, the time taken by an elf to make 8 present is 0.8 hours.
