The position of the fly is shown as cross in the diagram below
The distance of the fly from the ceiling is given as
We need to work out the distance

to be able to work out the value of

by the Pythagoras theorem



by Pythagoras theorem


The distance of the fly from the point P is 4m
You just divide 3 by 8. when 3 is inside the "house" and 8 is outside, 8 doesn't go into 3 so move on and 8 goes into 30 3 times. and so forth. 30-24=6 bring down the 0. 8 goes into 60 7 times. the decimal is 0.375. the percent is 37.5%.
I’m pretty sure it’s
Y=3x-3