a) 100%.................360
x.............................90
x=100*90/360=9000/360=25%
b)100%.................400
x..............................1000
x=1000*100/400=250%
c)100%..............2800
x......................308
x=308*100/2800=11
d)100%.................80
x............................20
x=100*20/80=2000/80=25
