The correct answer is: c. 18h
Step-by-step explanation:
Given
Length of small candle = 12 inches
Length of large candle = 15 inches
Let h be the number of hours.
Then
A small candle burns 1/2 inch every hour.
[tex]12-\frac{1}{2}h[/tex]
A large candle burns 2/3 inch every hour.
[tex]15-\frac{2}{3}h[/tex]
Putting both equal
[tex]12-\frac{1}{2}h=15-\frac{2}{3}h[/tex]
[tex]Subtracting\ 12\ from\ both\ sides\\12-12-\frac{1}{2}h=15-\frac{2}{3}h-12\\-\frac{1}{2}h=3-\frac{2}{3}h\\Adding\ \frac{2}{3}h\ on\ both\ sides\\-\frac{1}{2}h+\frac{2}{3}h = 3-\frac{2}{3}h+\frac{2}{3}h\\\frac{-3h+4h}{6} =3\\\frac{1}{6}h=3\\Multiplying\ both\ sides\ by\ 6\\\frac{1}{6}h*6=3*6\\h=18[/tex]
The candles will be of same height after 18 hours.
The correct answer is: c. 18h
Keywords: Linear equations, Word problems
Learn more about linear equations at:
- brainly.com/question/4786449
- brainly.com/question/4793866
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