Respostas

2014-08-12T11:07:52-03:00
80% de 40 = 40 x 80 ÷ 100
40 x 80 =3.200
3.200 ÷ 100 = 32
acertou 32 questoes
2014-08-12T11:09:14-03:00
32 questões....

x - 80
40 - 100

80x40=100x
3200=100x
x=3200/100
x=32