Final answer:
To find the greatest number of touchups Devon can afford, subtract the cost of the hair color analysis from the total amount she has to spend. Divide the remaining amount by the cost of each touchup to find the maximum number of touchups she can afford.
Step-by-step explanation:
To find the greatest number of touchups Devon can afford, we need to determine how many touchups she can buy with the remaining money after paying for the hair color analysis.
Devon initially pays $44.95 for the hair color analysis. After that, she has $232.90 - $44.95 = $187.95 left to spend on touchups.
Since each touchup costs $8.95, we can divide the remaining amount by the cost of each touchup to find the maximum number of touchups Devon can afford: $187.95 / $8.95 = 20.95.
Therefore, Devon can afford a maximum of 20 touchups. The correct answer is option b) 20.5 touchups.