Marija

A rock is thrown vertically up into the air. It reaches a maximum height 15m above point where it was released. What is its initial velocity? a) 17 m/s b) 26 m/s c) 14 m/s d) 20 m/s I know the answer is a) 17 m/s and I got it wrong thinking it was d) 20 m...

you have 9 options, 6 are the same and 3 are the same, so you do 9!/6!3!=84