a. 15%•420=15/100•420=3•21=63
b.25%•320=25/100•320=80
c.225%•120=225/100•120=9•30=270
d.40%•30=40/100•30=4•3=12
e.100%•125=100/100•125=125
f.12,5%80=12,5/100•80=10
a.10%•30%•70=10/100•30/100•70=3•7/10=21/10=2,1
b.25%•40%•150=25/100•40/100•150=1/4•4•15=15
c.40%•6%•500=40/100•6/100•500=4/10•6=2/5•6=12/5
d.30%•40%•1000=30/100•40/100•1000=3•4•10=120