<PRE><B>Question 774617</B>
A fort has provisions for 80 days. 
If after 15 days 500 men strengthen them and the food lasts 40 days thereafter,
 how many men were there in the fort?
:
Let m = no. of men originally at the fort
Then
80m = original number of man/food days
:
80m - 15m = 65m food days remaining after 15 days
:
40(m+500) = 65m
40m + 20000 = 65m
20000 = 65m - 40m
20000 = 25m
m = 20000/25
m = 800 men originally at the fort
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