SOLUTION: Water is leaking from a tank at a constant rate of 20% per hour. If yn denotes the amount of water at the beginning of the hour, in how many hours would Yn &#8804; y1/10?

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Question 374254: Water is leaking from a tank at a constant rate of 20% per hour. If yn denotes the amount of water at the beginning of the hour, in how many hours would Yn ≤ y1/10?
Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website!
I take this to mean the water left in the tank
is less than or equal to 1/10 of the starting
amount of water after hours
after 1st hour:
after 2nd hour:
after 3rd hour:
The pattern here is that after hours,
the amount of water left in the tank is

The problem wants to know when
The 's cancel from both sides leaving:

Note that

Take the log base 10 of both sides

Now I need to multiply both sides by
which reverses the < sign

Or, in whole numbers
The answer is

Unless I messed up- I think the approach is right

SOLUTION: Water is leaking from a tank at a constant rate of 20% per hour. If yn denotes the amount of water at the beginning of the hour, in how many hours would Yn &#8804; y1/10?

SOLUTION: Water is leaking from a tank at a constant rate of 20% per hour. If yn denotes the amount of water at the beginning of the hour, in how many hours would Yn ≤ y1/10?