Question

Em um posto de combustível, a gasolina custava R$ 3,90. Após um reajuste ela passou a custar R$ 4,80. Qual o percentual aproximado de aumento do combustível?

Answer 1

Explicação passo-a-passo:

Sabendo que 3,90 é 100% usamos o seguinte cálculo para descobrir a porcentagem de 4,80

$</strong><strong>\</strong><strong>s</strong><strong>f</strong><strong> \frac{3.90}{100} = \frac{4.80}{x}$

$</strong><strong>\</strong><strong>s</strong><strong>f</strong><strong> </strong><strong>0.039 = \dfrac{ \frac{24}{5} }{x}$

$</strong><strong>\</strong><strong>s</strong><strong>f</strong><strong> </strong><strong>0.039 = \frac{24}{5x}$

$</strong><strong>\</strong><strong>s</strong><strong>f</strong><strong> </strong><strong>0.195x = 24$

$</strong><strong>\</strong><strong>s</strong><strong>f</strong><strong> x = \frac{24}{0.195} = > \frac{1600}{13} = > 123.07$

$</strong><strong>\</strong><strong>s</strong><strong>f</strong><strong> </strong><strong>123.07 - 100 = </strong><strong>\</strong><strong>t</strong><strong>e</strong><strong>x</strong><strong>t</strong><strong>c</strong><strong>o</strong><strong>l</strong><strong>o</strong><strong>r</strong><strong>{</strong><strong>red</strong><strong>}</strong><strong>{</strong><strong>23.07\%</strong><strong>}</strong><strong>$

Espero ter ajudado !!!