Question

120 men got food provision for 200 days. After 5 days, 30 men died of an epidemic. The food will last for further:
A. 280 days
B. 260 days
C. 290 days
D. 252 days

Answer 1

Hint: Here we firstly calculate the total food available after 5 days by using simple computations and then calculate required number of days by dividing total food provisions available after 5 days by remaining men after 30 of them died.

Complete step-by-step answer:
Food provision was for 120 men for 200 days.
Total food which can be consumed by 1 man = $120\times 200=24000$
In 5 days, the food consumed by 120 men = $120\times 5=600$
Thus, remaining food provisions after 5 days = $24000-600=23400$
Men remaining after 5 days = $120-30=90$ (Because 30 men died of an epidemic)
Number of days it can last for remaining men is equal to the number of men left divided by remaining food provision.
Number of days it can last for remaining men = $\dfrac{23400}{90}=260$
Thus, the food will last for a further 260 days.
Hence, option B is correct.

Note: In this type of questions, we just need to find how much a certain commodity will last more or less for the remaining ones due to a decrease or an increase in the number of another commodity. Here we apply the rule that both the commodities vary inversely with each other and then calculate the required value using some easy mathematical computations.