A garrison of 200 men had provisions for 45 days. After 15 days, 40 more men join the garrison. Find the number of days for which the remaining food will last.
More the no. of men, lesser the days for which food last. So, it is an inverse proportion.
200 men had provisions for 45 days. After 15 days,200 men had provisions for 30days.
Now,
i) Number of men (x1) = 200 Provisions finished (y1) = 30 days
ii) after 15 days number of men joined are 40. Therefore,
Number of men after 15 days (x2) = 240
Let food last in number of days = y2
y2 = 
= 25 days
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