A car from a to B, 50 kilometers per hour. 4 / 5 hours. If the speed is reduced by 20%, how many hours can it reach? emergency

A car from a to B, 50 kilometers per hour. 4 / 5 hours. If the speed is reduced by 20%, how many hours can it reach? emergency

50×4/5÷[50×(1-20%﹚]=1
Then it can be reached in an hour