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?
time = distance / rate
(d / 14) + (d / 20) = 3 2/5
using LCD ... (10 d / 140) + (7 d / 140) = 3 2/5
17 d = 476