Part of field grazed by 4 goats in 1 day = 1/50
Part of field grazed by 1 goat in 1 day = (1/50) x 4 = 1/200
⇒ 4 g = 6 s [here, g = goats, and s = sheep]
⇒ 1 s = (4/6) g = (2/3) g
Now, 2 g + 9 s = 2 g + 9 x (2/3) g
= 2 g + 6 g = 8 g
∴ 8 goats can graze the field in (1/8) / 200 = 25 days
