308 miles per 11 gallons.
You need to find the amount of miles per 1 gallon.
dived the number of miles over gallons.
will look like:
miles
----------
gallons 
 it will look like for this problem
308
-------
11
308
-------- =28
11
28 miles per 1 gallon
        
             
        
        
        
Answer:
- 273 mL of 5%
- 117 mL of 15%
Step-by-step explanation:
Let q represent the quantity of 15% dressing used. Then the amount of 5% dressing is (390 -q). The amount of vinegar in the mix is ...
   0.15q + 0.05(390 -q) = 0.08(390)
   0.10q = 31.2 -19.5 = 11.7 . . . . . . subtract 0.05(390) and simplify
   q = 117 . . . . . . . . . . . . . . . . . . multiply by 10
   390-q = 273
The chef should use 273 mL of the first brand (5% vinegar) and 117 mL of the second brand (15% vinegar).
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<em>Additional comment</em>
You may have noticed that the value of q is (0.08 -0.05)/(0.10 -0.05)×390. The fraction of the mix that is the highest contributor is the ratio of the difference between the mix value and least contributor, divided by the difference between the contributors: (8-5)/(15-5) = 3/10, the fraction that is 15% vinegar. This is the generic solution to mixture problems.
 
        
             
        
        
        
<h3>
Answer:  $5.16</h3>
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Work Shown:
72% = 72/100 = 0.72
72% of $3.00 = 0.72*3.00 = 2.16
The price increases by $2.16 to get the final answer of 3.00+2.16 = 5.16 dollars
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We can find this answer through this alternative route:
1.72*3 = 5.16
The multiplier 1.72 represents an increase of 72% since 1.72 = 1 + 0.72 = 100% + 72% = 172%