SOLUTION: The fuel tank of your gas-powered scooter is 1/8 full. After adding 90 fluid ounces of fuel, the tank is 3/4 full. a. How much can the tank hold? b. How much fuel was originally

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: The fuel tank of your gas-powered scooter is 1/8 full. After adding 90 fluid ounces of fuel, the tank is 3/4 full. a. How much can the tank hold? b. How much fuel was originally       Log On


   

Question 838399: The fuel tank of your gas-powered scooter is 1/8 full. After adding 90 fluid ounces of fuel, the tank is 3/4 full.
a. How much can the tank hold?
b. How much fuel was originally in the tank?
c. How much fuel is in the tank when it is 2/3 full?
This is 6th grade math, not algebra and I need to teach my son how to solve this problem on his own. Thanks for your help.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The +90+ fluid ounces that was added made
up the difference between +1%2F8+ full and +3%2F4+ full
Note that +3%2F4+=+6%2F8+, and the difference +6%2F8+-+1%2F8+=+5%2F8+
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This is saying that +5%2F8+ of the tank holds +90+ fluid ounces
Each of these +5+ 1/8's holds +1%2F5+ of +90+
So +1%2F8+ of a tank holds +1%2F5+ of +90+
+8+ times +1%2F8+ is a full tank, so 1 tank contains
+%28+8%2F5+%29%2A90+
+%28+8%2F5+%29%2A90+=+720%2F5+
+720%2F5+=+144+
(a)
The tank holds 144 fluid ounces
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(b)
Originally there was +%281%2F8%29%2A144+=+18+ fluid ounces
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(c)
+%282%2F3%29%2A144+=+96+ fluid ounces
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Hope this helps