VJesus12 wrote: ↑

Fri Jul 24, 2020 6:45 am

It takes Mike 1 hour and 30 minutes to commute from home to work at an average speed of 40 miles per hour. If Mike returns home along the same route at an average speed of 45 miles per hour, how long does the return trip take?

A. 1 hour, 15 minutes

B. 1 hour, 20 minutes

C. 1 hour, 25 minutes
D. 1 hour, 30 minutes

E. 1 hour, 35 minute

deloitte247 wrote: ↑

Sun Jul 26, 2020 9:45 am

$$Average=\frac{dis\tan ce}{time\ taken}$$
Distance between Mike's home and workplace=>
$$=40\ miles\ per\ hour\ \cdot\ 1\frac{1}{2}=40\cdot1.5=60\ miles$$
Mike returns home along the same route at an average speed of 45 miles per hour.
$$Time\ taken\ for\ return\ trip=\frac{dis\tan ce}{speed}=\frac{60miles}{45miles\ per\ hour}$$ $$=\frac{4}{3}hours$$
$$=1\frac{1}{3}hours$$
=> 1 hour 20 minutes

Answer = option B