Official Quant thread for CAT 2013

MBA CAT 2024
3861
@Brooklyn said:
The square root of the harmonic mean of the roots of the equation(5 + rt(2) )x2 − (4 + rt(5) )x + 8 + 2rt(5) = 0 is.A. ± 3 B. ± 4 C. 2 D. None of thesePost approach for others
B...HM is 2ab/(a+b) where a and b are roots..
3862
@Brooklyn said:
The square root of the harmonic mean of the roots of the equation(5 + rt(2) )x2 − (4 + rt(5) )x + 8 + 2rt(5) = 0 is.A. ± 3 B. ± 4 C. 2 D. None of thesePost approach for others


+-2
3863
@Brooklyn said:
logic too plz
Let the roots be a and b
then ab= (8+2root5)/(5+root2)
a+b=(4+root5)/(5+root2)
We have to find (2ab/a+b)^1/2
So root2*(ab/a+b)^1/2
Put the values .2 aa jayega ..wats the OA??
3864
@Brooklyn Ans is --D i.e. ‚Ä…2
3865
@saurav5517 said:
Let the roots be a and bthen ab= (8+2root5)/(5+root2)a+b=(4+root5)/(5+root2)We have to find (2ab/a+b)^1/2So root2*(ab/a+b)^1/2Put the values .2 aa jayega ..wats the OA??
@Nihilist1002 said:
@Brooklyn Ans is --D i.e. ą2
3866
@Nihilist1002 said:
@Brooklyn Ans is --D i.e. ą2
OA 😃
3867

Mene bhi to yahi use kia...Galati kaha hui 😐

3868
@Brooklyn said:
The square root of the harmonic mean of the roots of the equation(5 + rt(2) )x2 − (4 + rt(5) )x + 8 + 2rt(5) = 0 is.A. ± 3 B. ± 4 C. 2 D. None of thesePost approach for others
2ab/a+b ka sqrt kar de bass

+- 2 ?
3869
@realslimshady said:
N=(2^15)*(3^12) how many factors of n^2 are less than n but do not divide n completely a.387 b.180 c.208 d.310

b... 180??????

3870

Oh got it....root nikalna tha :splat:

3871
@gs4890 said:
iska seedha formula hain=> (total no. of factors of n^2 + 1) / 2 - total no. of factors of nso, 180 aaega
I think (total no. of factors of n^2 ) / 2 +1 - total no. of factors of n hoga
3872



@gs4890 said:
iska seedha formula hain=> (total no. of factors of n^2 + 1) / 2 - total no. of factors of nso, 180 aaega
yaar ye formula kaise aya? explination please
3873
@rachit_28 said:
I think (total no. of factors of n^2 ) / 2 +1 - total no. of factors of n hoga
3874
If
u1 = rt(3),u2 = rt(3 rt(3)) ,u3 = rt(3 rt(3 rt(3))) , etc,., u10 : u9 is:
(A) rt(3) (B)3^1/10 (C) 3^1/20 (D) None of these


Something same came in CAT this year 😃 Past IIFT q 😁
3875
@gs4890 said:
correct. my bad.
3876
@Brooklyn said:
Ifu1 = rt(3),u2 = rt(3 rt(3)) ,u3 = rt(3 rt(3 rt(3))) , etc,., u10 : u9 is:(A) rt(3) (B)3^1/10 (C) 3^1/20 (D) None of theseSomething same came in CAT this year Past IIFT q
3^1/10?
3877
@Brooklyn said:
Ifu1 = rt(3),u2 = rt(3 rt(3)) ,u3 = rt(3 rt(3 rt(3))) , etc,., u10 : u9 is:(A) rt(3) (B)3^1/10 (C) 3^1/20 (D) None of theseSomething same came in CAT this year Past IIFT q
B ?
I checked for u2/u1, it came out 3^1/2 , so u10/u9 should be 3^1/10
3878
@Brooklyn said:
If
u1 = rt(3),u2 = rt(3 rt(3)) ,u3 = rt(3 rt(3 rt(3))) , etc,., u10 : u9 is:
(A) rt(3) (B)3^1/10 (C) 3^1/20 (D) None of these
D ..answr should be 3^(1/2^10)?
PS: Itne dino baad thread par post kar raha hu n saare galat ho rahen hain ..:(
3879
@Brooklyn it dat c (3)^1/20
3880
@Torque024 said:
3^1/10?
@rachit_28 said:
B ?I checked for u2/u1, it came out 3^1/2 , so u10/u9 should be 3^1/10
nop
ur u2/u1 is wrong sorry 😛