swerve wrote:Al, Lew, and Karen pooled their funds to buy a gift for a friend. Al contributed $2 less than 1/3 of the cost of the gift and Lew contributed $2 more than 1/4 of the cost. If Karen contributed the remaining $15, what was the cost of the gift?
A. $24
B. $33
C. $36
D. $43
E. $45
The OA is C.
Please, can anyone explain this PS question? I can't get the correct answer. I need help. Thanks.
Hi swerve,
We can use a shortcut to answer this question and avoid algebraic equations.
If we knew the cost of the gift, we could easily calculate the amounts contributed by Al and Lew.
Since the answer choices represent the cost of the gift, and one of the answer choices must be correct, we can Plug In the Answers.
When Plugging In the Answers, always begin with choice C, unless there is good reason to begin with another choice (for example, in a question that asks for the "least" or "greatest" amount, we might want to begin with choice A or E).
In this question, there's no reason to begin with another choice, so begin with choice C.
If the total cost of the gift was $36, and Al contributed $2 less than 1/3 the total cost, then Al contributed ($36/3) - $2 = $10.
Similarly, if the total cost was $36, and Lew contributed $2 more than 1/4 the total cost, then Lew contributed ($36/4) + $2 = $11.
If Karen contributed the remaining $15, then total cost of the gift was $10 + $11 + $15 = $36.
Since this answer matches the criteria in the question stem, the correct answer must be choice
C.
Hope this helps.
