barakhaiev wrote:
I have not found any discussions about this question, thus I am posting it here. Please, help, I do not get what is the point here.
This is from gmatclub test 14, question 16
A stationery store sells pens and pencils. If the price of each item is expressed as a non-zero whole number of cents, how much do 5 pencils cost?
1. 5 pencils and 3 pens cost 30 cents.
2. 4 pencils and 4 pens cost 32 cents.
# Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient
# Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient
# BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient
# EACH statement ALONE is sufficient
# Statements (1) and (2) TOGETHER are NOT sufficient
Question Stem : What is the cost of 5 pencils?
Let p refer to price of one pencil and q refer to price of one pen.
We are given that both p and q must be non zero whole numbers (1,2,3,4,5.... and so on).
St. (1) : 5p + 3q = 30
This can be written as
p = \frac{30-3q}{5} = 6 - \frac{3q}{5}This implies that in order for p to be a whole number, q must be a multiple of 5. Also, we can see that if q = 10, then p will be equal to 0. Since this cant be possible, q must be less than 10. Also, since q itself cant be 0, it must be greater than 0. The only multiple of 5 that satisfies this condition is the number 5 itself.
Thus we get q = 5 and p = 3.
Statement is sufficient.
St. (2) : 4p + 4q = 32
This can be written as p + q = 8
Thus, since different sets of values of p and q can satisfy this condition, it cannot be sufficient.
Answer : A
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