Question

Stiind ca a/18=b/25 , aflati cate procente reprezinta numarul a din numarul b . 

Answer 1

a/18=b/25

a=18b/25

p%  din b= a

p/100 * b=  18b/25

p/100=18b/25/b

p/100=18b/25 * 1/b

p/100= 18/25

p=100*18/25

p=4*18

p=72%

Answer 2

$\frac{a}{18} = \frac{b}{25}$ 

facand produsul mezilor si al extemilor ⇒ a=$\frac{18b}{25}$

 x% ·b=a

$\frac{x}{100}$ · b= $\frac{18b}{25}$ 

$\frac{x}{100}$= $\frac{18b}{25}$ :b 

$\frac{x}{100}$ = $\frac{18}{25}$

x= $\frac{100x18}{25}$

x=72%