Official Quant thread for CAT 2013

MBA CAT 2024
28785
@amresh_maverick said:
Two line segments AB and CD bisect each other. If their ends are joined to form a quadrilateral ADBC, then which of the following is(are) true? I. ˆ ADB = 90 ° II. AD = AC III. AD = BC
let the diagonals intersect at E.now triangle AED and triangle CEB will be congruent to each other.so AD=BC.the other two may or may not be true depending on the length of sides
28786

Questions 41 answer is only 1

And 42 ans is c to vbhvgupta
28787
@amresh_maverick said:
Thirty six numbers are filled in the cells of a matrix as shown in the figure given below. Six numbers are chosen from the matrix such that no two numbers belong to the same row or the same column. In how many ways can the numbers be chosen?
6!=720
28788
@vbhvgupta 42-b
28789
@vbhvgupta said:
bhai explain??
when we put x=y^-1=z^3=k
x=k
y=k^-1
z=k^1/3

the no resulting would be 1 , -1, -3, -5 which are in AP
28790
@falcao said:
@vbhvgupta 42-b
approach
28791
@vbhvgupta -see one of the answers is definitely 1 as log 1 =0. so i just substituted options a and b and i got b as the answer
28792
@vbhvgupta said:
approach
put the values , it will satisfy
28793
@vbhvgupta said:
Q42 43
43... c
28794
@Narci said:
43... c
D
28795
@vbhvgupta said:
D
howcome?

let x=2..

x/x+1 = 2/3 =0.67

log(x+1) = log 3 = 0.477

x> x/x+1 > log(x+1)
28796

On a biased dice every odd number appears 4 times as frequently as every even number. If the dice is rolled 3 times, what is the probability that the sum is 17 or more?


A. 1/3375
B. 12/625
C. 13/625
D. 13/3375.


OA is D but i am getting 13/125.
Plz let me know if any one gets it right.
Thanks

28797

@vbhvgupta said:
D
bhai c hoga ek baar phir check kar le.
28798
@falcao said:
bhai c hoga ek baar phir check kar le.
karta hun..

Checked bhai...D
28799
@vbhvgupta said:
karta hun..Checked bhai...D
43 ka has to be C....
28800
@ravi6389 said:
On a biased dice every odd number appears 4 times as frequently as every even number. If the dice is rolled 3 times, what is the probability that the sum is 17 or more?A. 1/3375B. 12/625C. 13/625D. 13/3375.OA is D but i am getting 13/125.Plz let me know if any one gets it right.Thanks
the outcomes can be written as 1,3,5 ( 4 times) and 2,4,6 (1 time each)
total number of outcomes for 3roll ... 15*15*15 = 3375
outcomes for which sum is 17 or 18 (19 not possible) ... 665,656,566 (12 occurences as 5 has a weightage of 4) and 666 ( 1 occurence) .. so total possible occurence = 13

hence probability = 13/3375
28801
@vbhvgupta said:
Q42 43
43 . x/(x+1) has to be less than 1, x has to be greater than log(x+1), and log(x+1) for x = 1, is log(basee)2 which is more than 2/3,,, hence d..
28802
@Narci said:
howcome?let x=2..x/x+1 = 2/3 =0.67log(x+1) = log 3 = 0.477x> x/x+1 > log(x+1)
perhaps when it is not mentioned the base to be taken is e.. and not 10,, and ur answer is still wrong, cannot be c either.. because for values of x greater than 10, log(x+1)>1 and x/x+1 is always less than 1
28803
@pratskool said:
the outcomes can be written as 1,3,5 ( 4 times) and 2,4,6 (1 time each)total number of outcomes for 3roll ... 15*15*15 = 3375outcomes for which sum is 17 or 18 (19 not possible) ... 665,656,566 (12 occurences as 5 has a weightage of 4) and 666 ( 1 occurence) .. so total possible occurence = 13hence probability = 13/3375
Thanks pratskool bhai. I got the denominator wrong.took it 5 *5*5 rather than taking it as 15 ( 4 1s + 4 3s + 4 5s + 1 '2' + 1 '4' + 1 '6' . So total possibility for one throw of dice is 4 + 4 + 4 + 1 + 1 + 1 = 15). :)
28804
Find the maximum value of abc(b + c) if ab + bc + ca = 2