SOLUTION: A group of 156 tourists had enough food for a stay of 125 days in the mountains. However, just before they left, n tourists left the group, and this meant that the group had enough

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Question 1095729: A group of 156 tourists had enough food for a stay of 125 days in the mountains. However, just before they left, n tourists left the group, and this meant that the group had enough food to stay for another 70 days. How many left the group?
Found 2 solutions by josmiceli, greenestamps:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The number of tourists would be inversely
propertional to the number of days they
could stay in the mountains
------------------------------
+156+=+k%2A%28+1%2F125+%29+
+k+=+19500+
-----------------
+156+-+n+=+k%2A%28+1%2F%28+125+%2B+70+%29%29+
+156+-+n+=+19500%2A%28+1%2F195+%29+
+156+-+n+=+100+
+n+=+56+
56 tourists left

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!

josmiceli's solution is valid; however, usually inverse proportion problems are solved with less work if you use the idea that the product of the two quantities is a constant. So instead of doing
156+=+k%2F125
to solve for the constant k, simply do
156%2A125+=+n%2A195

The solution to that equation is n=100; that means the number of tourists that left is 156-100 = 56.