Many Test Takers would take an Algebraic approach to this prompt (which is fine). Since the answers ARE numbers, and the question asks for the retail price of the machine, we can TEST THE ANSWERS.
From the prompt, we're given a number of Facts:
1) A machine was purchased at a wholesale price of $90
2) It was sold after a 10% discount to the RETAIL price
3) The profit on the sale was 20% of the WHOLESALE price
We're asked to find the retail price of the machine.
Since the wholesale price was $90 and the profit was 20% of the wholesale price ([.2] = $18), the retail price would have to be above $108, but not that much greater than that.
Let's start by TESTing Answer C: $120....
Retail Price = $120
10% discount off = $120 - (.1)(120) = 120 - 12 = 108
20% profit on wholesale price = 90 + (.2)(90) = 90 + 18 = 108
These two numbers MATCH, so this MUST be the answer!
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