Official Quant thread for CAT 2013

MBA CAT 2024
4281
@surajsrivastav said:
Mukesh, Suresh, and Diensh travel form Delhi to Mathura to attend JanmasthmiUtsav. They have a bike which can carry only two rides at a time as per traffic rules. Bike can be driven only by Mukesh. Mathura is 300km form Delhi. All of them can walk at 15km/hr. All of them start their journey from Delhi simultaneously and are required to reach Mathura at the same time. If the speed of bike is 60km/hr then what is the shortest possible time in which all there can each Mathura at the same time.
11 hours?
Mukesh takes one of them to Mathura---> 5 hours
In that 5 hours, one of them walked 75 km
Next 3 hours..mukesh travels ---180 km while the person walking travels a total of 120km
Hence when mukesh meets the man who is walking they only have to cover a total of 180 km to reach mathura, which will take 3 more hours
Total time = 5+3+3 = 11
4282
@surajsrivastav said:
Mukesh, Suresh, and Diensh travel form Delhi to Mathura to attend JanmasthmiUtsav. They have a bike which can carry only two rides at a time as per traffic rules. Bike can be driven only by Mukesh. Mathura is 300km form Delhi. All of them can walk at 15km/hr. All of them start their journey from Delhi simultaneously and are required to reach Mathura at the same time. If the speed of bike is 60km/hr then what is the shortest possible time in which all there can each Mathura at the same time.
11 hrs?
4283
@surajsrivastav said:
Mukesh, Suresh, and Diensh travel form Delhi to Mathura to attend JanmasthmiUtsav. They have a bike which can carry only two rides at a time as per traffic rules. Bike can be driven only by Mukesh. Mathura is 300km form Delhi. All of them can walk at 15km/hr. All of them start their journey from Delhi simultaneously and are required to reach Mathura at the same time. If the speed of bike is 60km/hr then what is the shortest possible time in which all there can each Mathura at the same time.
65/7 by any chance??
4284
@soumitrabengeri said:
11 hours? Mukesh takes one of them to Mathura---> 5 hoursIn that 5 hours, one of them walked 75 kmNext 3 hours..mukesh travels ---180 km while the person walking travels a total of 120kmHence when mukesh meets the man who is walking they only have to cover a total of 180 km to reach mathura, which will take 3 more hoursTotal time = 5+3+3 = 11
Nope sir... Mukesh takes one of them to some point(between delhi and mathura) and drop him.. return for the other one, who is also walking towards mathura..
4285
@rachit_28 said:
Find the coefficient of x^27 in (x^2 + 2x)^15.
OA is 3640.
4286
@ScareCrow28 fantastic.. approach????
4287
@surajsrivastav said:
Nope sir... Mukesh takes one of them to some point(between delhi and mathura) and drop him.. return for the other one, who is also walking towards mathura..
Did not read that all of them have to reach mathura at the same time

4288
@soumitrabengeri said:
Did not read that all of them have to reach mathura at the same time
4289
@surajsrivastav said:
Mukesh, Suresh, and Diensh travel form Delhi to Mathura to attend JanmasthmiUtsav. They have a bike which can carry only two rides at a time as per traffic rules. Bike can be driven only by Mukesh. Mathura is 300km form Delhi. All of them can walk at 15km/hr. All of them start their journey from Delhi simultaneously and are required to reach Mathura at the same time. If the speed of bike is 60km/hr then what is the shortest possible time in which all there can each Mathura at the same time.
http://www.pagalguy.com/posts/4053452
4290
@surajsrivastav As indicated in figure distances are covered by bike and men..
10x/3+6x = 300
==> x= 900/28
First one man will cover 5x/3 distance on foot in 100/28 hours..
Next x distance in 60/28 hrs..
By this time bike will drop the second man at a distance of 5x/3 from destiation and pick up the first man..
the second man will then take 100/28 hrs to cover 5x/3 distance..

total (100+60+100)/28 = 65/7 hrs
4291
@chillfactor said:
can you pls explain this ?

PQ = RS = x (as time taken by Suresh and Dinesh are same.
4292
@surajsrivastav said:
@ScareCrow28 fantastic.. approach????
Since all of them have to reach at the same time..Hence only possibilty is Mukesh takes 1 person to some point between Delhi and Mathura..drops him there and returns for other..and after some time all reach at the same time..
Now, Delhi______A______B______Mathura
Mukesh drops one of them at B and returns and then finds the other at A
Hence.. DB+AB = 4 DA (speeds are in ratio 4:1)
=> AB = 3/2 * DA
You will get equations solving which gives.. DA= 600/7, AB=900/7..BM=600/7
Time= 600/7*15 + (900+600)/7*60 = 65/7
Office me hun....can't write all equations
4293
@catter2011 said:
can you pls explain this ?PQ = RS = x (as time taken by Suresh and Dinesh are same.
PQ is the distance travelled by Suresh on Bike and rest he travelled by walking. RS is the distance travelled by Dinesh on bike and rest he travelled by walking. Now they are reaching at the same time, we can say that they travelled on the bike for the same time

So, PQ = RS = x
4294
The term independent of x in the binomial expansion of (3x/2 - 1/3*x)^10 is

-63/8

63/8

-21/8

21/8

@ScareCrow28 ruk kyu gaye, questions daalo naa ..
4295
@rachit_28 -63/8 right?
4296
@rachit_28 said:
The term independent of x in the binomial expansion of (3x/2 - 1/3*x)^10 is-63/863/8-21/821/8@ScareCrow28 ruk kyu gaye, questions daalo naa ..
-63/8
x^10(3/2 - 1/3x^2)^10
10C5(3/2)^5(-1/3)^5 = -63/8
Yaar ab tum he dalo :P
4297
@rachit_28 : Independent term of x will be : 10C5 * -(1/2)^5 = -63/8
4298
@rachit_28 said:
The term independent of x in the binomial expansion of (3x/2 - 1/3*x)^10 is-63/863/8-21/821/8@ScareCrow28 ruk kyu gaye, questions daalo naa ..
-63/8
4299
Find the coefficient of x^r in {1/(1-x)*(3-x)}

@ScareCrow28 tumne Probability ke itne saare questions daale ki sab bhag gaye, 2-4 kuch aur daalo, tab rang jamega :P
4300
@rachit_28 said:
Find the coefficient of x^r in {1/(1-x)*(3-x)}@ScareCrow28 tumne Probability ke itne saare questions daale ki sab bhag gaye, 2-4 kuch aur daalo, tab rang jamega
3^-1 * (3^-0+ 3^-1 + 3^-2 + ...3^-r) ??
I don't want everyone to go away because of me :P