If 540 kg of grass would feed 100 cows for 9 days, then how many days would 900 kg of grass feed 50 days?

50 days  10 days  20 days  30 days

30 days

Formula used: $\frac{M_1 \times  D_1}{W_1}$ = $\frac{M_2 \times  D_2}{W_2}$ Here, $M_1 = 100 cows, D_1 = 9 days, W_1 = 540 kg$,           $M_2 = 50 cows, D_2 = ?, W_2 = 900 kg$    ⇒ $\frac{100 \times  9}{540}$ = $\frac{50 \times  D_2}{900}$  ⇒ $D_2$ = 30 days