Question

Starting at home, Jessica traveled uphill to the toy store for 12 minutes at just 10 mph. She then traveled back home along the same path downhill at a speed of 30 mph.

What is her average speed for the entire trip from home to the toy store and back?

Answer 1

cause she used 12 min with 10mph per hour, then we know that she used 30 mph per hour, we can use 12 divide by 3 then we get she spend 4mins in the way back to home.
4+12=16mins
16/60=4/15
（30+10）times 4/15=10.66666....... or 10.7