Bunuel wrote:
gmatzac wrote:
The ratio of the number of women to the number of men to the number of children in a room is 5:2:7, respectively. What is the total number of people in the room?
(1) The total number of women and children in the room is 12.
(2) There are fewer than 4 men in the room.
Came across this in the GMAC practice exam. Should we not consider zero as an option for the number of men in statement two? When they give the ratio, we should assume there are at least some people in the room?
From the stem it follows that there are at least 5 women, 2 men and 7 children in the room.*******
Me too, I fell into the "zero men" trap. However, I do not believe that it is clear from the question stem that there MUST be people in the room.
Of course a ratio of 5*0:2*0:7*0 = 0:0:0 would not make much sense, but it is a possibility.
There is a better reason for eliminating the "zero men" option however:
GMAT data sufficiency questions are made in a way that the 2 options NEVER result in contradictory results. This is no hard science, but in the hundreds of questions we are resolving in preparation for the test there is no single one with a conflicting data sufficiency result. Note this is my experience, if not true please send me the reference of an official DS question that illustrates else.
So, because the question stem in 1) gives us women + children = 12, there are people in the room. I am not talking about carrying over information from 1) to 2), but I am just saying that contradictory results are impossible (i.e. calculating a result for option 2 of zero people in the room, while 1) gave 14 people as a result).
1) the total number of women and children in the room is 12
2) There are fewer that 4 men in the room
Hence the # of men must be a member from the set {1,2,3}. Only possibility in this question that satisfies the ratio constraint is: men = 2x = 2 so total number of people is 14.
SUFFICIENT
Answer DBunuel, if this is what you meant with "it is clear from the question stem", then I agree with you. If this is not what you meant, then this might help some people who fell into the "zero men" trap to be suspicious of a contradictory result they have calculated on a data sufficiency question.