el1981 wrote:

Please help to solve this question.

How many more men than women are in the room?

1. There is a total of 20 women and men in the room.

2. The number of men in the room equals the square of the number of women in the room.

Ans should be C.

S1: w+m=20. Can't find value of either from here without more info.

S2: m=w^2. We know the relationship of m to w, but cannot establish actual values b/c we don't know the total number of men and women.

Ex/ if m=4 w=2. Total is 6. But also could be: m=16 w=4. Total is 20. So not suff.

Together we know the relationship and we have the total value of w and m.

So if m=w^2, plug it in. w^2+w=20---> w^2+w-20=0 (w+5)(w-4)=0 ---> w=-5 or 4. We can't have negative women so value of women is 4.

Thus value of men is 16 so there are 12 more men that women in the room.