Question

A) 2/5 de 30= ?
B)2/5 de ? =30
C)28% de 150= ?
D)3% de ? =12
E) Em fração irredutivel: ? de 350= 154
F)Em porcentagem: ? de 350= 154

Answer 1

A ) $\frac{2.30}{5} = \frac{60}{5} = 12$

B ) $\frac{2}{5} x = 30 =\ \textgreater \ \frac{2x}{5} = 30 =\ \textgreater \ 2x = 30.5 = 150 =\ \textgreater \ x = \frac{150}{2} =\ \textgreater \ x = 75$

C)  28% ⇒ $( \frac{28}{100} ).150 = \frac{4200}{100} = 42$

D ) 3% = $( \frac{3}{100} )x =12 =\ \textgreater \ \frac{3x}{100} = 12 =\ \textgreater \ 3x = 100. 12 =\ \textgreater \ x = \frac{1200}{3} =\ \textgreater \ x = 400$

E ) $\frac{350:14}{154:14} = \frac{25}{11}$

F ) X% de 350 = 154 ⇒ $\frac{x}{100}.350 = 154$ ⇒$\frac{350x}{100} = 3,5x$ ⇒ $x = \frac{154}{3,5} = 44%$