Answer:
9 3/8 inches
Explanation:
Inches of candle : hours it burned
= 5 inches : 4 hours
How far has it burned after 7 1/2 hours?
Let
x = how far it has burned (inches)
Inches of candle : hours it burned = x inches : 7 1/2 hours
Equate both ratios
5 inches : 4 hours = x inches : 7 1/2 hours
5/4 = x ÷ 7 1/2
5/4 = x ÷ 15/2
5/4 = x * 2/15
5/4 = 2x/15
Cross product
5 * 15 = 4 * 2x
75 = 8x
x = 75/8
x = 9 3/8 inches
x = how far it has burned (inches) = 9 3/8 inches