Question

Chile rode her bicycle from her house directly to the library in 4 minutes. The library is 1 mile from her house.

Answer 1

Answer:

Part A) Speed of Chloe's bicycle from her house to the library = 15 mph

part B) Average speed  = 10 mph

Step-by-step explanation:

Chile rode her bicycle from her house directly to the library in 4 minutes. The library is 1 mile from her house.

Distance between house and library = 1 mile

Time taken from house to library = 4 minutes

As we know, 60 minutes =  1 hour

So, 4 minutes $=\dfrac{1}{15}\ h$

$\text{Speed} = \dfrac{\text{distance}}{\text{time}}$

$\text{Speed}=\dfrac{1}{1/15}=15\text{ mph}$

Part A:

Speed of Chloe's bicycle from her house to the library = 15 mph

Part B: Chloe's trip back to her house took twice as long as her trip to the library.

• From house to library:-

Distance =  1 mile

Time $=\dfrac{1}{15}\ h$

• From library to house

Distance =  1 mile

Time $=\dfrac{2}{15}\ h$

$\text{Average speed}=\dfrac{\text{Total distance}}{\text{Total time}}$

$\text{Average speed}=\dfrac{1+1}{\frac{1}{15}+\frac{2}{15}}$

$\text{Average speed}=\dfrac{2}{\frac{3}{15}}$

Average speed  = 10 mph

Answer 2

Chile's speed is 60/4 * 1 = 15 mph
Chile's speed on her way back = 15/2 = 7.5 mph
Chile's average speed = (15+7.5) / 2 = 11.25 mph