Question

Stiind ca 2/5 din pasarile unui gospodar sunt gaini adica 140 si 3/7din rest sunt rate.cate pasari sunt de altfel?

Answer 1

$x - nr. \: total \: de \: pasari$

$\frac{2}{5} \times x = 140$

$\frac{2x}{5} = 140$

$2x = 5 \times 140$

$2x = 700$

$x = \frac{700}{2}$

$x = 350$

$350 - 140 = 210 \: (rest)$

$\frac{3}{7} \times 210 = 3 \times 30 = 90 \: (rate)$

$140 + 90 + a = 350$

$230 + a = 350$

$a = 350 - 230$

$a = 120 \: (pasari \: de \: alt \: fel)$