A garrison of 400 men had food for 27 days. After 3 days a reinforcement of 200 men arrived. For how many more days will the remaining food last now?

Question: A garrison of 400 men had food for 27 days. After 3 days a reinforcement of 200 men arrived. For how many more days will the remaining food last now?

Solution:
After 3 days, food having for = 27 - 3 = 24 days
After arriving 200 men, total men = 400 + 200 = 600 men

400 men can eat the food for 24 days
1 man can eat the food for 24 × 400 days
600 men can eat the food for (24 × 400)/600 days
= 16 days