What is the predicted height of a new 18 year old drama student in inches ?

(98 points) i need with 5 questions. answer definitions are welcomed, but not necessary.

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

The serenity and the mystic are sail boats. the serenity and the mystic start at the same point and travel away from each other in opposite directions. the serenity travels at 16 mph and the mystic travels at 19 mph. how far apart will they be in 3 hours?