Some Math problems from GMAt prep software

[cfanowgmat]

1)


What is the result when x is rounded to the nearest hundreth?
(1) When x is rounded to the nearest thousandth the ersult is 0.455
(2) The thousandths digit of x is 5



2)
Is (1/q) > r/(2+r^2) ?


1) p=r

2) r>0


3)
Team A has 500 members. Team B has 200 members. Among these members there are 20 siblings pairs, each consisting of one member from each team. If one member is to be selected at random from each team, what is the probability that the 2 members selected will be a sibling pair?

[adnanbbukhari]

For Q1) I think 1) is Sufficient because we can find x based on the value provided

for Q2) If If it is a typing mistake than 1) should be q=r
In this case if you replace q with r in statement in question and simplify
you get r^2/(2+r^2) < 1 which is always true for all the values of r in real number system so this is sufficient.

Hope this helps.

[cfanowgmat]

1) For 1, gmat prep sofware says ans is C


2)
I have a query regrding this.

What is it was .4546 . In this case when rounded to hundreth , wont we get .45

I guess we need both A and B for this.

[cfanowgmat]

1) For 1, gmat prep sofware says ans is C


2)
I have a query regrding this.

What is it was .4546 . In this case when rounded to hundreth , wont we get .45

I guess we need both A and B for this.

I made a mistake before.

1) For Q2, gmat prep sofware says ans is C


For Q1,

I have a query.


We can have 2 cases.

1) No is 0.4546. On rounding we get 0.45

2) No is 0.4553. On rounding we get 0.46

In both cases, on rounding to nearest thousandth, we get 0.455.

I guess we need both A and B for this.

[pranavc]

Why is C right for Q2? A should be sufficient. especially q=r. Any input would be appreciated.

[gmatsure76]

what if r is -1 then it will not satisfy

[gmatsure76]

hi cfanow , can you post the OA's for the questions ur posted

for 1 it is C

for 2 it is C

and for 3 is the ans 1 /5000

also for the 2 questions remember when u solve using first stem ,always have a look at the second stem for some hint ,here it says r > 0 , so might be r needs to be > 0 , so try plugin in opposite and there u see it will fail , for most of the DS questions the other stem gives a hint usually

[pranavc]

what if r is -1 then it will not satisfy

Good call. That makes sense. Thanks a lot.