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

D. 3:00 p.m.

Explanation:

d = Distance = 320 miles

s = Speed =
`60\ \text{mph}=(60)/(3600)=(1)/(60)\ \text{miles/s}`

Time taken is given by

`t=(d)/(s)\\\Rightarrow t=(320)/((1)/(60))\\\Rightarrow t=19200\ \text{s}`

40 minutes break is
`40* 60=2400\ \text{s}`

Total time taken is
`19200+2400=21600\ \text{s}=(21600)/(60* 60)=6\ \text{hours}`.

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