Ryan's marbles = x
Marie has 4 times less marbles then Ryan would have if he lost 15 marbles (it means he would have x-15)
So, Marie marbles = (x-15):4
If Ryan lost 75 marbles (it means he would have x-75), he would have 1 1/2 times as many marbles as Marie.
We got an equation:
Multiply both sides by 8:

Add 600 and subtract 3x on both sides:

Divide both sides by 5:

Answer: Ryan have 111 marbles.
6 or 9 maybe I’m not real for sure though
As far as I can tell, is just asking for the type, so that'd be a tangential line to the globe, or a tangent line, see picture below
The height is now 4.8 inches because 6 x 0.8 is 4.8