Official Quant thread for CAT 2013

@sowmyanarayanan said:
XAT 2012 Q: Nikhil's mother asks him to buy 100 pieces of sweets worth Rs. 100/-. The sweet shop has 3 kinds of sweet kajubarfi, jamun and sandesh costing 10, 3 and .5 rupees respectively. If Nikhil decides to buy at least one sweet of each type how many jamuns ahould he buy?
1?
@sowmyanarayanan said:
XAT 2012 Q: Nikhil's mother asks him to buy 100 pieces of sweets worth Rs. 100/-. The sweet shop has 3 kinds of sweet kajubarfi, jamun and sandesh costing 10, 3 and .5 rupees respectively. If Nikhil decides to buy at least one sweet of each type how many jamuns ahould he buy?
10k+3j+.5s=100
k+j+s=100;
we get 19k+5j=100
possible for k=5 for sum to be less than 100
j=(100-95)/5 = 1?
One of the data ninjas at a reputed analyst firm goes to make coffee for herself and two colleagues. The company has two Italian coffee machines, each capable of making 5 coffees before a refill is required. The first machine she tries is empty. If it is early in the morning, and people randomly choose which coffee machine to use, what is the probability that the second machine will have enough coffee to fulfill her order? You can assume that if both machines are empty, they get refilled immediately. Your answer needs to be a simplified fraction.


@anytomdickandhary @naga25french @deedeedudu @krum @vijay_chandola
@Zedai @scrabbler @techsurge @chillfactor @Brooklyn @sujamait @soumitrabengeri @rkshtsurana @Estallar12 @ScareCrow28

P.S : As and always requested, ek pyara sa detailed logic, coz i won't be able to provide an OA for this.

@sowmyanarayanan said:
XAT 2012 Q: Nikhil's mother asks him to buy 100 pieces of sweets worth Rs. 100/-. The sweet shop has 3 kinds of sweet kajubarfi, jamun and sandesh costing 10, 3 and .5 rupees respectively. If Nikhil decides to buy at least one sweet of each type how many jamuns ahould he buy?
KB + J + S = 100
20*KB + 6*J + S=200
Subtracting both

J = 20 - 19*KB/5

KB can only be 5
Hence J= 1
@nick_baba said:
One of the data ninjas at a reputed analyst firm goes to make coffee for herself and two colleagues. The company has two Italian coffee machines, each capable of making 5 coffees before a refill is required. The first machine she tries is empty. If it is early in the morning, and people randomly choose which coffee machine to use, what is the probability that the second machine will have enough coffee to fulfill her order? You can assume that if both machines are empty, they get refilled immediately. Your answer needs to be a simplified fraction.@anytomdickandhary@naga25french@deedeedudu@krum@vijay_chandola@Zedai @scrabbler @techsurge @chillfactor @Brooklyn @sujamait @soumitrabengeri @rkshtsurana @Estallar12 @ScareCrow28 P.S : As and always requested, ek pyara sa detailed logic, coz i won't be able to provide an OA for this.
Coffee machine-1 is empty.
Hence she moves to machine-2

Now, Machine-2 has 5 possibilities with it
It has coffee for 5, 4, 3, 2 or 1 Cups.

Here Favourable conditions are: 3, 4 or 5

Hence Prob = 3/5 ??
@nick_baba said:
let K, J and S be the legends for the no. of sweets of each typeso we have 10K+ 3J+ 5S= 100-- 3J + 5(S + 2K)= 100now we have to get max. no. of J and since each of them has a min. value of 1,we have to get 3J as max. multiple of 5 which satisfies the above eqn.for S=3 and K=1 we get min of 5(S + 2K)= 25.hence max. J can be 25. (since 3J=75)
It's 0.5S and not 5S.
It can never be >1 Otherwise there would be no solution.
@ScareCrow28 said:
It's 0.5S and not 5S.It can never be >1 Otherwise there would be no solution.
are haan yaar i misread that .5 with 5.....but had it been 5 then it would have been 25
@nick_baba said:
One of the data ninjas at a reputed analyst firm goes to make coffee for herself and two colleagues. The company has two Italian coffee machines, each capable of making 5 coffees before a refill is required. The first machine she tries is empty. If it is early in the morning, and people randomly choose which coffee machine to use, what is the probability that the second machine will have enough coffee to fulfill her order? You can assume that if both machines are empty, they get refilled immediately. Your answer needs to be a simplified fraction.

@nick_baba @ScareCrow28
What is the importance of below sentence in this question.

You can assume that if both machines are empty, they get refilled immediately


@sowmyanarayanan said:
XAT 2012 Q: Nikhil's mother asks him to buy 100 pieces of sweets worth Rs. 100/-. The sweet shop has 3 kinds of sweet kajubarfi, jamun and sandesh costing 10, 3 and .5 rupees respectively. If Nikhil decides to buy at least one sweet of each type how many jamuns ahould he buy?
10k + 3j + 1/2s = 100
20k + 6j + s = 200 ---1
k+j+s = 100

19k + 5j = 100
k=5
j=1

so,s=94

jamun=1
@htomar said:
@nick_baba@ScareCrow28 What is the importance of below sentence in this question. You can assume that if both machines are empty, they get refilled immediately
It means Machine 2 can never be empty. It would have coffee for atleast 1 cup! We would not take any option of 0 Cup.
@htomar said:
@nick_baba@ScareCrow28 What is the importance of below sentence in this question. You can assume that if both machines are empty, they get refilled immediately
u tell..
@nick_baba said:
are haan yaar i misread that .5 with 5.....but had it been 5 then it would have been 25
It can never be 5 bhaiya je. A+B+C=100 and 10A+3B+5C=100 Both can't be true at the sme time na.
@nick_baba said:
One of the data ninjas at a reputed analyst firm goes to make coffee for herself and two colleagues. The company has two Italian coffee machines, each capable of making 5 coffees before a refill is required. The first machine she tries is empty. If it is early in the morning, and people randomly choose which coffee machine to use, what is the probability that the second machine will have enough coffee to fulfill her order? You can assume that if both machines are empty, they get refilled immediately. Your answer needs to be a simplified fraction.
@anytomdickandhary @naga25french @deedeedudu @krum @vijay_chandola
@Zedai @scrabbler @techsurge @chillfactor @Brooklyn @sujamait @soumitrabengeri @rkshtsurana @Estallar12 @ScareCrow28
P.S : As and always requested, ek pyara sa detailed logic, coz i won't be able to provide an OA for this.

1st machine empty
she moves to second
total cases 1,2,3,4,5 (0 not because if both were empty it would be refilled)
favourable 3,4,5
3/5
@nick_baba said:
One of the data ninjas at a reputed analyst firm goes to make coffee for herself and two colleagues. The company has two Italian coffee machines, each capable of making 5 coffees before a refill is required. The first machine she tries is empty. If it is early in the morning, and people randomly choose which coffee machine to use, what is the probability that the second machine will have enough coffee to fulfill her order? You can assume that if both machines are empty, they get refilled immediately. Your answer needs to be a simplified fraction.@anytomdickandhary@naga25french@deedeedudu@krum@vijay_chandola@Zedai @scrabbler @techsurge @chillfactor @Brooklyn @sujamait @soumitrabengeri @rkshtsurana @Estallar12 @ScareCrow28 P.S : As and always requested, ek pyara sa detailed logic, coz i won't be able to provide an OA for this.

Ist, 2nd
Empty, (5,4,3) Fave
Empty, (5,4,3,2,1) Total P(E)=3/5
PS: If we assume that if both machines are empty, they get refilled immediately. Then second machine will never get emptied as 1st is already empty then P(E)=1. o.O



@ScareCrow28 said:
It means Machine 2 can never be empty. It would have coffee for atleast 1 cup! We would not take any option of 0 Cup.

@nick_baba said:
u tell..
I thought both of them cannot be empty simultaneously... and considering that.. as soon as machine two becomes empty if refills again immediately (coz machine 1 is already empty) .. In such a case probability comes out to be 1.


@nick_baba said:
One of the data ninjas at a reputed analyst firm goes to make coffee for herself and two colleagues. The company has two Italian coffee machines, each capable of making 5 coffees before a refill is required. The first machine she tries is empty. If it is early in the morning, and people randomly choose which coffee machine to use, what is the probability that the second machine will have enough coffee to fulfill her order? You can assume that if both machines are empty, they get refilled immediately. Your answer needs to be a simplified fraction.@anytomdickandhary@naga25french@deedeedudu@krum@vijay_chandola@Zedai @scrabbler @techsurge @chillfactor @Brooklyn @sujamait @soumitrabengeri @rkshtsurana @Estallar12 @ScareCrow28 P.S : As and always requested, ek pyara sa detailed logic, coz i won't be able to provide an OA for this.
[ (1/2^5+1/2^6+1/2^7)*3/5 ] / [ (1/2^5+1/2^6+1/2^7)*3/5 + (1/2^8+1/2^9+1/2^10)*2/5]
=(21/640) / [(21/640) + (7/2560)]
=21*4/(21*4+7)
=12/13
@gautam22 said:
0 kyun nahi agar both empty hain to sirf usi ko fill karega aur le jayega joki immediately ho jata hai......plz correct me if i m wrong
The machines get refilled only after both of them get empty. After Machine-1 gets empty people have to use Machine-2. If Machine-2 also gets empty then they both get refilled simultaneously.
Hence we won't take 0
@gautam22 said:
0 kyun nahi agar both empty hain to sirf usi ko fill karega aur le jayega joki immediately ho jata hai......plz correct me if i m wrong
bhai it syas if both were empty they both would have been refilled not other wise cause then when he goes for 1st it should have been refilled
if he goes for 2nd and it was empty it implied both together empty but this is not possible as both would have been refilled on the last person filling from the second machine and not when the next person checks for coffe
@krum said:
[ (1/2^5+1/2^6+1/2^7)*3/5 ] / [ (1/2^5+1/2^6+1/2^7)*3/5 + (1/2^8+1/2^9+1/2^10)*2/5]=(21/640) / [(21/640) + (7/2560)]=21*4/(21*4+7)=12/13
@Torque024 said:
Ist, 2ndEmpty, (5,4,3) FaveEmpty, (5,4,3,2,1) Total P(E)=3/5PS: If we assume that if both machines are empty, they get refilled immediately. Then second machine will never get emptied as 1st is already empty then P(E)=1. o.O
@techsurge said:
1st machine emptyshe moves to secondtotal cases 1,2,3,4,5 (0 not because if both were empty it would be refilled)favourable 3,4,53/5
@ScareCrow28

u decide wat could be a possible sol??

@krum buddy thoda lang please..
@nick_baba said:
@ScareCrow28u decide wat could be a possible sol??@krum buddy thoda lang please..
@gautam22 said:
thoda samjhao sir ye.....
yaar baye's lagaya hai, :splat:

@anytomdickandhary sir, aap hi bataein kya hoga __/\__