39% de 3800
=39/100×3800
=0,39×3800
=1482
50% de 3800
=50/100×3800
=0,5×3800
=1900
49% de 2800
=49/100×2800
=0,49×2800
=1372
90% de 1800
=90/100×1800
=0,9×1800
=1620
