Answer:
107%p
not much explanation needed here, just conversion of units.
500 at 40 each = £20000
To make a profit he needs to make more than £20000
20 broke so he sold 500-20 = 480 at 45 each.
480 x 45 = 21600
Profit = 21600 -20000 = 1600
His profit was £1,600
x=90
y=78
z=70
Now
or,90+78+70
or,238 answer.
i believe x= 36.3
72.6/2=36.3
:)