Official Quant thread for CAT 2013

MBA CAT 2022
2021
@Torque024 said:
Data sufficiencyQ. The roots of the equation Ax^3 + Bx^2 + Cx + D = 0, where A > 0, are in AP. Find all possible roots of the equation Bx^2 + Cx + D = 0.I. One of the roots of the equation Ax^3 + Bx^2 + Cx + D = 0 is 0.II. C
cannot be answered. getting everythin 0
2022
@ani4588 said:
Historical Data of a retail store indicated that 40 percent of all the customers that entered the store make a purchase .Determine the probability that exactly two out of the next three make a purchase?
36/125?
2023
@ani4588 said:
Historical Data of a retail store indicated that 40 percent of all the customers that entered the store make a purchase .Determine the probability that exactly two out of the next three make a purchase?
Purchase=40%=2/5
Not Purchase=60%=3/5
Let persons be A,B,C
so for exact 2=>ABC'+BCA'+CAB'=(2/5*2/5*3/5)*3=36/125
2024
@ani4588 said:
Historical Data of a retail store indicated that 40 percent of all the customers that entered the store make a purchase .Determine the probability that exactly two out of the next three make a purchase?
(.4)^2 X .6 X 3 = 288/1000?
2025
@Torque024 said:
Data sufficiencyQ. The roots of the equation Ax^3 + Bx^2 + Cx + D = 0, where A > 0, are in AP. Find all possible roots of the equation Bx^2 + Cx + D = 0.I. One of the roots of the equation Ax^3 + Bx^2 + Cx + D = 0 is 0.II. C
share the OA?
2026
@ani4588 said:
Historical Data of a retail store indicated that 40 percent of all the customers that entered the store make a purchase .Determine the probability that exactly two out of the next three make a purchase?
2/5*3/5*2/5+2/5*2/5*3/5+3/5*2/5*2/5 = 36/125
2027
@ani4588 said:
Historical Data of a retail store indicated that 40 percent of all the customers that entered the store make a purchase .Determine the probability that exactly two out of the next three make a purchase?
P(p) = 2/5
P(np) = 3/5

Probability = 2/5*2/5*3/5 * 3 = 36/125 I guess.
2028
@ani4588 said:
Historical Data of a retail store indicated that 40 percent of all the customers that entered the store make a purchase .Determine the probability that exactly two out of the next three make a purchase?
36/125?

4/10 * 4/10 * 6/10 * 3C2
= 36/125
2029
@maddy2807 said:
share the OA?
Solution is : Question can be answered by using both the statements together but not by either of the statements alone.
2030
Find the minimum value of h^2+k^2. Where 3h-4k+45=0...
approach without differentiation...
2031
@Torque024 said:
Solution is : Question can be answered by using both the statements together but not by either of the statements alone.
but u cannot find a fix value for the roots. please post the complete solution. coz i m stuck with one positive and one negative root.
i guess i m making a mistake sumwhere
2032
@pankaj1988 said:
Find the minimum value of h^2+k^2. Where 3h-4k+45=0...approach without differentiation...
getting the value as 85 for h=-7 and k=6..is it correct?
2033
@pankaj1988 said:
Find the minimum value of h^2+k^2. Where 3h-4k+45=0...approach without differentiation...
h^2+k^2 min karna hai = (h+k)^2-2hk means hk max krna hoga for given h+k which can happen only when h=k
3h-4k=-45
h=k=(45/7)
min value= 2*(45/7)^2
Confirm?
2034
@pankaj1988 said:
Find the minimum value of h^2+k^2. Where 3h-4k+45=0...approach without differentiation...
is ans 81?
then i hv a method
2035
@soumitrabengeri said:
getting the value as 85 for h=-7 and k=6..is it correct?

@Torque024 said:
h^2+k^2 min karna hai = (h+k)^2-2hk means hk max krna hoga for given h+k which can happen only when h=k3h-4k=-45h=k=(45/7)min value= 2*(45/7)^2Confirm?
81
@maddy2807 said:
is ans 81? then i hv a method
method plz
2036
@maddy2807 said:
but u cannot find a fix value for the roots. please post the complete solution. coz i m stuck with one positive and one negative root.i guess i m making a mistake sumwhere
2037
@pankaj1988 said:
81 method plz
i used Cauchy Schwartz inequality here.

h^2+k^2 to be minimum
4k-3h=45

(h^2+k^2)(4^2+3^2)>=(4k-3h)^2
(h^2+k^2)(25)>=45^2
h^2+k^2>=81

2038
Given that n is a natural number, when is n^4 + 4 prime?
2039
Solve the factorial equation a!b! = a! + b! + c!
2040
@rkshtsurana said:
Given that n is a natural number, when is n^4 + 4 prime?
1?