Answer: [tex]\text{The average speed for the entire trip from home to the gift store and back}=15\text{ mph}[/tex]
Step-by-step explanation:
Time taken to travel from uphill to the gift store =18 minutes
∴ [tex]t_1=18\ minutes=\frac{18}{60}\ hour=0.3\ hour[/tex]
Speed of Ishaan from uphill to the gift store =10 mph
We know that [tex]\text{Distance}=\text{Speed}\times\text{time}[/tex]
[tex]\\\Rightarrow\d_1=10\times0.3=3\ \text{miles}[/tex]
We he traveled back, the distance remains same
Thus [tex]d_2=d_1=3\text{ miles}[/tex]
We know that
[tex]\text{time}=\frac{\text{Distance}}{\text{speed}}\\\Rightarrow\ t_2=\frac{3}{30}=0.1\text{ hour}[/tex]
[tex]\text{The average speed}=\frac{\text{total distance}}{\text{total time}}\\=\frac{3+3}{0.3+0.1}\\\\=\frac{6}{0.4}\\\\=\frac{60}{4}=15\\\\\Rightarrow\text{The average speed}=15\text{ mph}[/tex]
[tex]\text{The average speed for the entire trip from home to the gift store and back}=15\text{ mph}[/tex]
