Question

Razvan a rezolvat in 7 zile 105 probleme. In cate zile rezolva 150 de probleme, daca ritmul zilnic e acelasi?

Answer 1

7/y=105/150
⇒y=7·150/105
⇒y=150/15
⇒y=10[zile];

Answer 2

7 zile ......................... 105 probleme 
x zile ......................... 150 probleme
-------------------------------------------------------
$\frac{7}{x}$  =  $\frac{105}{150}$

x = $\frac{7 * 150 }{105}$

x = $\frac{1050}{105}$

x = 10 zile