The following question is from a Kaplan CAT. I do not agree with the answer, can someone see if they agree or disagree? To me (2) is simply a ratio that doesn't indicate the total cost of typewriters and calculators, but please let me know if you disagree.
A business bought r typewriters at $100 per typewriter and s calculators at $50 per calculator. What is the total cost of the typewriters and calculators?
(1) The s calculators cost $200
(2) 2 r + s = 10
Statement (1) BY ITSELF is sufficient to answer the question, but statement (2) by itself is not.
Statement (2) BY ITSELF is sufficient to answer the question, but statement (1) by itself is not.
Statements (1) and (2) TAKEN TOGETHER are sufficient to answer the question, even though NEITHER statement BY ITSELF is sufficient.
EITHER statement BY ITSELF is sufficient to answer the question.
Statements (1) and (2) TAKEN TOGETHER are NOT sufficient to answer the question, requiring more data pertaining to the problem.
[Show/hide explanation]
You're given the price of a typewriter and the price of a calculator. You're asked for the total cost of the typewriters and calculators, which can be written as 100 r + 50 s . Statement (1) tells you that the calculators cost $200. You can use this information to solve for s , but you can't find the total cost, so (1) is insufficient. Statement (2) tells you that 2 r + s = 10. Notice that the coefficients in the statement, 2 for r and 1 for s , are in the same ratio as the expression you derived from the stem. In fact, if you multiply both sides of the equation of statement (2) by 50, you'll get 100 r + 50 s = 500. This gives us the total cost of the calculators and typewriters, so (2) is sufficient.
A business bought r typewriters at $100 per typewriter and s calculators at $50 per calculator. What is the total cost of the typewriters and calculators?
(1) The s calculators cost $200
(2) 2 r + s = 10
Statement (1) BY ITSELF is sufficient to answer the question, but statement (2) by itself is not.
Statement (2) BY ITSELF is sufficient to answer the question, but statement (1) by itself is not.
Statements (1) and (2) TAKEN TOGETHER are sufficient to answer the question, even though NEITHER statement BY ITSELF is sufficient.
EITHER statement BY ITSELF is sufficient to answer the question.
Statements (1) and (2) TAKEN TOGETHER are NOT sufficient to answer the question, requiring more data pertaining to the problem.
[Show/hide explanation]
You're given the price of a typewriter and the price of a calculator. You're asked for the total cost of the typewriters and calculators, which can be written as 100 r + 50 s . Statement (1) tells you that the calculators cost $200. You can use this information to solve for s , but you can't find the total cost, so (1) is insufficient. Statement (2) tells you that 2 r + s = 10. Notice that the coefficients in the statement, 2 for r and 1 for s , are in the same ratio as the expression you derived from the stem. In fact, if you multiply both sides of the equation of statement (2) by 50, you'll get 100 r + 50 s = 500. This gives us the total cost of the calculators and typewriters, so (2) is sufficient.
