Question 167498
distance = rate * time

in this instance distances will be equal so if clipper is 8(T)
.........................................and if riverboat is 10(T-(1/2))

the are equal to each other because distance is equal
8T=10(T-(1/2))
8T=10T-5
2T=5---->{{{highlight(T=(5/2)hours)}}}clipper travel time

so if its 9:00am when he leaves it is 11:30am when the river boat over takes him