Data Sufficiency

If there are 400 women at College X and 200
students live off-campus, how many students
does College X have?
(1) 120 women live off-campus.
(2) There are half as many men at College X as
there are students who live on-campus.

Does anyone know the ans to this problem?

Acc to me ans is B. But OA is C.

If there are 400 women at College X and 200
students live off-campus, how many students
does College X have?
(1) 120 women live off-campus.
(2) There are half as many men at College X as
there are students who live on-campus.

ans- at college; 400-women, men-?
outside- 120- women, men?
so stst 1 is not sufficient

st2 let num of men in campus be x, then (400 + x)/2 = x
x= 400. hence total = 400+400+200=1000.
st 2 is sufficient.

i hope this makes u comfortable. if u find sth esoteric do reply to me.
cheers

how do u decide how many students live ON CAMPUS?

There is no Mention of the number of students who live on campus...

I would have to go with E.

The closest match is I can get to 280 women on campus and 120 off campus.
that leave me with 80 men off campus . Still no information on how many male students live on campus.

Does it make any sense ?

I think it is E as well.

Anyone else?

imo b

Nidhs wrote:If there are 400 women at College X and 200
students live off-campus, how many students
does College X have?
(1) 120 women live off-campus.
(2) There are half as many men at College X as
there are students who live on-campus.

Does anyone know the ans to this problem?

Answer should be C.

(1) and (2) alone does not converge to any answer. Lets check them together.
Data: 400 women, 200 off campus student (men+women), 120 women off campus so
200-120=80 men off campus
400-120 = 280 women on-campus
say the number of men student living on campus is M. Then 280+M women and men lives on campus
(2) says that M+80 = (280+M)/2. Solve for M. M = 120
So # of students are 400 women +200 men = 600

Probelm solved. Answer is C.

luvaduva wrote:I think it is E as well.

Anyone else?

I think C

Stmt 1 provides number of women on campus 400-120=280
Stmt 2 provides that total on campus is 2 times number of men

x=number of men
x-80 = number of men on campus
number of men on campus (x-80)
plus number of women on campus (280)
= twice the number of men (2x)
x-80+280=2x
x=200

------------off-----on----Total
men-------80----120----200
women---120---280----400
TOTAL----200---400----600

i still think u can get the same ans by using only st2
consider the table below

The question stem provides us with the foll

------- M-------- W
C ------------------

OC ------------------- 200
---------------- 400

Now st2 tells us that
There are half as many men at College X as there are students who live on-campus.
Therefore
------- M----------W
C ------------------------ 2x

OC ---------------------- 200
------- x -------- 400-------

2x+200=x+400
x=200
Total no of students is 600.

Any inputs?

I agree with Nidhs. Because, Students on Campus + Out of campus = men + women, which is the same as 400+x=2x+200

Stuart, what's our mistake???

Nidhs wrote:If there are 400 women at College X and 200
students live off-campus, how many students
does College X have?
(1) 120 women live off-campus.
(2) There are half as many men at College X as
there are students who live on-campus.

Does anyone know the ans to this problem?

From the original we know that there are 400 women and 200 off campus students. We want to know the total # of students.

So, if we know either the total # of men OR the total # of on-campus students, we can solve.

(1) 120 women live off campus - gives us neither piece of info we need.

(2) #men = 1/2 the # of on campus. Since we don't know either of these variables, we can't solve for the other. Not good enough by itself.

Combined:

(1) tells us that there are 280 women who live on campus. When we combine this with (2) we get 2 equations:

M = 1/2 (OnCamp)

and M = OnCamp - 280

Now we have 2 equations and 2 unknowns, we can solve for M (and since we know W, we can answer the question): choose (C).

davidforsberg wrote:I agree with Nidhs. Because, Students on Campus + Out of campus = men + women, which is the same as 400+x=2x+200

Stuart, what's our mistake???

Hmm.. maybe I'll change my mind on this question!

We do know that w + m = on + off
w=400
off = 200
on = 2m

4 equations, 4 unknowns - we should be able to solve for everything.

400 + m = 2m + 200
200 = m

So total # = 600

Looks good!

so you're saying that the correct answer is B instead of C???

davidforsberg wrote:so you're saying that the correct answer is B instead of C???

Yah, seems like (2) should be sufficient alone.