Question

Shelly hopped onto her bicycle and pedaled to the park at 14 miles per hour. Then she whizzed back at 20 miles per hour. If the total trip took 3 2/5 hours how far was it to the park?

Answer 1

we know that
speed=distance/time
distance=speed*time

in this problem
speed1=14 miles/hour
speed2=20 miles/hour
average speed=[14+20]/2-----> 17 miles/hour
time=3 2/5 hour-----> (3*5+2)/5----> 17/5 hours

distance=17*(17/5)----> 57.8 miles

the answer is
57.8 miles