Description for Correct answer:
Because, For 1000 men, provision lasts for 48 days.

Therefore, For 1 man, provision lasts for \( \Large \left(48 \times 1000\right) \) days.

For \( \Large \left(1000 + 600\right) \) men,

provision will last for \( \Large \frac{48 \times 1000}{1600} \) days

Therefore, Required number of days

= \( \Large \frac{48 \times 1000}{1600} = 3 \times 10 \) = 30 days