a)5% = 5/100= 0,05

b)145% = 145/100= 1,45

c)0.15% =0,15/100= 0,0015

d)6.45% = 6,45/100= 0,0645

e)0.09% = 0,09/100 = 0,0009

f)31/4% = 7,75% = 0,0775