Answer:
1 hour 15 Minutes
Explanation:
The glider begins its flight
mile above the ground.
Distance above the ground after 45 minutes =
![(3)/(10) \:mile](https://img.qammunity.org/2021/formulas/mathematics/college/bb8tkel55ozqcf764w4khultd06kerk675.png)
Change in height of the glider
![=(3)/(4)-(3)/(10) \\\\=(15-6)/(20)\\\\=(9)/(20) miles](https://img.qammunity.org/2021/formulas/mathematics/college/d2uzhk4amz97mp6ul59u2q19x97u5mbpez.png)
Next, we determine how long the entire descent last.
Expressing the distance moved as a ratio of time taken
![(9)/(20) \:miles : 45 \:minutes\\\\(3)/(10)\:miles:x \:minutes\\\\x=45X(3)/(10)/(9)/(20) =30 Minutes](https://img.qammunity.org/2021/formulas/mathematics/college/jafavuenrjfdctylori1ellpkjtcgkdknz.png)
Therefore: Total Time taken =45+30=75 Minutes
=1 hour 15 Minutes