There are 300 men in a group. They have food for 30 days. After 10 days, 100 more men join the group. Remaining food will last for how many days?
Answer & explanation
Correct answer: option 3
Initially, men = 300, days = 30 days,
After 10 days,
100 more men are added,
remaining number of days = 30 - 10 = 20 days
300 men had provisions for 20 days,
1 man had provisions for (300 x 20) days {less men, more days}
400 men had provisions for $\frac{300 \times 20}{400}$ days = 15 days
Hence, the remaining food will last for 15 days.