How Is Average Speed Calculated for a Round Trip with a Lunch Break?

[black_hole]

Homework Statement

Calculate the average speed of a complete round trip in which the first 148.6 km is covered at 84.6 km/hr, followed by a 1.2-hour lunch and the final 148.6 km is covered at 50.6 km/hr.

Homework Equations

The Attempt at a Solution

148.6+148.6/.569+1.2+.341 = wrong

 

[tiny-tim]

Hi black_hole!

erm …

speed = distance/time, so time = distance/speed. ​