Question

Estimate the time Juanita will arrive at her aunt's home 320 miles away if she leaves at 9:00 a.m., drives about 60 miles per hour, and stops
for a 40 minute break halfway.

A 12:00 p.m.

B. 1:00 p.m.

c. 2:00 p.m.

D. 3:00 p.m.

E. 4:00 p.m.

Answer 1

Answer:

D. 3:00 p.m.

Step-by-step explanation:

d = Distance = 320 miles

s = Speed = $60\ \text{mph}=\dfrac{60}{3600}=\dfrac{1}{60}\ \text{miles/s}$

Time taken is given by

$t=\dfrac{d}{s}\\\Rightarrow t=\dfrac{320}{\dfrac{1}{60}}\\\Rightarrow t=19200\ \text{s}$

40 minutes break is $40\times 60=2400\ \text{s}$

Total time taken is $19200+2400=21600\ \text{s}=\dfrac{21600}{60\times 60}=6\ \text{hours}$.

So, the entire trip took 6 hours. 6 hours after 9 a.m. is 3 p.m.