a)
the average speed, well it does 10 ft in 1.6 secs, so is simply their quotient, 10/1.6 = 6.25 ft/s on average.
b)
over the horizontal, well, it covered horizontally 9.25 ft in those 1.6 secs, so their quotient is 9.25/1.6 = 5.78125 ft/s on average.
c)
we don't know the vertical distance, but
so, it covered vertically about 3.8 ft in those 1.6 secs, so then 3.8/1.6 = 2.375 ft/s on average