Official Quant thread for CAT 2013

@maddy2807 said:
@ScareCrow28@soumitrabengeri@ayushnasaif I can deduce wellacc to naga sir... since the prob to hit the target is 1/2so if we hit 6 target. obviously 3 will hit the target. and 1 more is taken to ensure that the prob is achieved. otherwise it wud hv been 1.but still with this method. prob remains less than .9please suggest frnds.
if 3 will hit( and this itself is wrong...we cant assume half will hit when the number of outcomes is so low...) Then we have a 100% prob of it destroying the target in 6 hits flat..I gave 6 as the answer on the same lines, but was pretty sure it was wrong..
@ScareCrow28
@ayushnasa
@soumitrabengeri
salo mere upar ku chad rahe ho... mene thodi question banaya hai...
@ScareCrow28 said:
In the meantime:We have 3 pastures with grass of identical height, density and growth rate. The first is 3 1/3 acres and can feed 12 oxen for 4 weeks. the second is 10 acres and can feed 21 oxen for 9 weeks. The third is 24 acres. How many oxen can be fed on these pastures for 18 weeks?
36?
@maddy2807 said:
@ScareCrow28@ayushnasa@soumitrabengerisalo mere upar ku chad rahe ho... mene thodi question banaya hai...
:mg:
@deedeedudu said:
36?
Kya baat hai!
@maddy2807 said:
@ScareCrow28@ayushnasa@soumitrabengerisalo mere upar ku chad rahe ho... mene thodi question banaya hai...
Upar chadne me bhot bhot maza ata hai 😁 Huhahahaha!
@deedeedudu said:
36?
approach?
@ScareCrow28 said:
In the meantime:We have 3 pastures with grass of identical height, density and growth rate. The first is 3 1/3 acres and can feed 12 oxen for 4 weeks. the second is 10 acres and can feed 21 oxen for 9 weeks. The third is 24 acres. How many oxen can be fed on these pastures for 18 weeks?
36??
@ScareCrow28 bhai approach batao... i m getting 18.
2 variable equation ka use kara hai kya?
for 7:
(0.9)^3 * [ 2c2 + 3c2(0.1) + 4c2(0.1^2) + 5c2(0.1^3) + 6c2(0.1^4) + 7c2(0.1^5) ]
=0.729*{1+0.3+0.06+0.01+0.0015+0.00021}= 0.99997699

for 6:
0.9^3* [ 2c2 + 3c2(0.1) + 4c2(0.1^2) + 5c2(0.1^3) + 6c2(0.1^4) ]
=0.729 * [1+0.3+0.06+0.01+0.0015] = 0.9998235

@ScareCrow28 i thought in this way.....but anyway this is also wrng... :\

@krum bhai, ek baar isko dekho:
Probability that I hit a target is 1/2. The target is destroyed if 3 shots hit the target. What is the minimum number of shots that I should try, so that the probability that I destroy the target is more than 0.9 ?1)6 2)7 3)8 4)9
@maddy2807 said:
approach?
Let the initial amount of grass be x and growth rate be y
For the 1st pasture
10/3(x+4y)=12*4
For second
10(x+9y)=21*9
From the above equations we get
x=10.8,y=0.9
For the 3rd pasture
24(10.8+18*0.9)/18=No of oxen
@ScareCrow28 said:
Nai dunga
to approach bata do!!
grass/(oxen*week) = (k(10/3)(4) + h(10/3))/48... (1)

grass/(oxen*week) = (k(10)(9) + h(10))/189... (2)

where, k is the growth rate and h is the height of grass.
solving them we got k = .9 and h = 10.8

use it for the 3rd situation
and we get 36
@maddy2807 said:
@ScareCrow28 bhai approach batao... i m getting 18.2 variable equation ka use kara hai kya?
We have to take into consideration the fact that the grass is growing at a constant rate..
Let k be the growth rate of the pastures. The amount of grass that grows depends on the time and the size of the pasture,
grass = k*area*time
--- grass = k * (10/3) * 4
but we have an initial amount of grass
So---grass = k * (10/3) * 4 + l(10/3)---(1)
Similarly for other as well... 2 variables 2 equations..you will gert the answer as 36 oxens :D
Let k be a fixed odd positive no. find minimun value of x^2 +y^2, where x, y are nonnegative interger and x+y =k ?
Mai options nahi dunga :P
@ScareCrow28 said:
Let k be a fixed odd positive no. find minimun value of x^2 +y^2, where x, y are nonnegative interger and x+y =k ? Mai options nahi dunga
1 ?
@ScareCrow28 said:
Let k be a fixed odd positive no. find minimun value of x^2 +y^2, where x, y are nonnegative interger and x+y =k ? Mai options nahi dunga
(((k-1)/2)^2)+(((k+1)/2)^2)
@rachit_28 said:
1 ?
@ScareCrow28 said:
bhai maine x = 0 and y = 1 maan liya, usse k= 1 ho gaya
then x^2 + y^2 = 1 ho gaya.
isme kya galat ho gaya ? :neutral:
@rachit_28 said:
bhai maine x = 0 and y = 1 maan liya, usse k= 1 ho gayathen x^2 + y^2 = 1 ho gaya.isme kya galat ho gaya ?
Bhai, k=3 ke saath try kar ke dekh :mg: