SOLUTION: Hi! I hope this is an acceptable use of this website. My husband has recently added a hydrogen generator to his engine to increase his gas mileage. He used to get 11 miles to a

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: Hi! I hope this is an acceptable use of this website. My husband has recently added a hydrogen generator to his engine to increase his gas mileage. He used to get 11 miles to a       Log On


   



Question 158569: Hi! I hope this is an acceptable use of this website. My husband has recently added a hydrogen generator to his engine to increase his gas mileage. He used to get 11 miles to a gallon but now he gets 18 miles to a gallon.
We can't seem to figure out how to come up with the percentage of increase that is. We will need to use this formula a lot since he will be building one for my SUV next and is considering helping others with them. It feels silly to not be able to figure this out. He used a calculator to come up with an answer and I used longhand division and multiplication by hand and the weird thing is that we came up with different answers. I double-checked mine so I know mine is correct but since I'm not sure I used the correct formula, I still feel unsure of my answer.
Thanks in advance for your help!
Susan

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
the increase from 11 to 18 is 7 __ the % increase is based on the original value

7 is 78% (approx) of the original value of 11 __ this is the percentage increase