GMAT Practice Question: The hard drive, monitor, and printer for a certain desktop computer system cost a total of...
Question
The hard drive, monitor, and printer for a certain desktop computer system cost a total of 2,500USD. The cost of the printer and monitor together is equal to \frac{2}{3} of the cost of the hard drive. If the cost of the printer is 100USD more than the cost of the monitor, what is the cost of the printer?
- 800USD
- 600USD
- 550USD
- 500USD
- 350USD
Topics: word problems, translations, simultaneous equations
Solution
Step 1
We first create variables for each item to avoid ambiguity
H = \text{cost of the hard drive} M = \text{cost of the monitor} P = \text{cost of the printer}
Step 2
We translate the statement that all three costs sum to 2,500USD
H + M + P = 2500
Step 3
We translate that the combined cost of printer and monitor equals two-thirds of the hard drive cost
P + M = \frac{2}{3}H
Step 4
We translate that the printer costs 100USD more than the monitor
P = M + 100
Step 5
We isolate the hard drive cost in terms of the monitor cost using algebra
2M + 100 = \frac{2}{3}H H = 3M + 150
Step 6
We substitute expressions for H and P into the total-cost equation
(3M + 150) + M + (M + 100) = 2500
Step 7
We collect like terms and move constants to solve for M
5M + 250 = 2500 5M = 2250
Step 8
We divide both sides by 5 to find the monitor cost
M = 450
Step 9
We then find the printer cost by adding 100USD to the monitor cost
P = 450 + 100 = 550
Answer
550USD
