Official Quant thread for CAT 2013

@pirateiim478 said:
How many numbers between 1 to 1000 are not divisible by 2,3 or 5?@jain4444 _/\_ after long time!!
990*1/2*2/3*4/5 = 264...
now count the numbers (manually) co-prime to 30 and between 990 to 1000 -> 991 and 997..

hence total 266 such numbers...

1)In how many ways can 12 balls be divided among 3 people such each can get a max of 6 balls .

2) a +b +c+ d = 90 , a,b,c,d

Let me know how to take care of this max condition ?

@saurabhlumarrai said:
answer 72 hai kya...???
it is 72
@anuragu79 said:
1)In how many ways can 12 balls be divided among 3 people such each can get a max of 6 balls .2) a +b +c+ d = 90 , a,b,c,d Let me know how to take care of this max condition ?
1) A...B...C
3...3...6 -> 12c3*9c3*3!/2!
3...4...5 -> 12c3*9c4*3!
4...4...4 -> 12c4*8c4
2...5...5 -> 12c2*10c5*3!/2!
2...4...6 -> 12c2*10c4*3!
1...6...5 -> 12c1*11c6*3!

hope i haven't missed any case...

2) (45-a) + (45-b) + (45-c) + (45-d) = 90

aese karke karte hai iss wale ko....koi aur method ho kisi ke pass toh batana...

PS - I am in office that is why not solving it completely...srry for that..

if : BELGIS x 6 = GISBEL.
the value of SI + BELGIS + BELI + ES + LEGI = ?
@Logrhythm said:
1) A...B...C3...3...6 -> 12c3*9c3*3!/2!3...4...5 -> 12c3*9c4*3!4...4...4 -> 12c4*8c42...5...5 -> 12c2*10c5*3!/2!2...4...6 -> 12c2*10c4*3!1...6...5 -> 12c1*11c6*3!hope i haven't missed any case...2) (45-a) + (45-b) + (45-c) + (45-d) = 90aese karke karte hai iss wale ko....koi aur method ho kisi ke pass toh batana... PS - I am in office that is why not solving it completely...srry for that..
Even I'm not sure about both of these...
For 2nd one:
according to your solution, a+b+c+d=90 which gets us back to original equation..And then ans will be 93C3...
But if we think logically it should be less than that no???due to the max. condition some cases wont appear in ans...
@jain4444 said:
if : BELGIS x 6 = GISBEL.the value of SI + BELGIS + BELI + ES + LEGI = ?
BELGIS=142857
SO ANS=75+142857+1425+47+2485=146889
@anuragu79 said:

1)In how many ways can 12 balls be divided among 3 people such each can get a max of 6 balls .

2) a +b +c+ d = 90 , a,b,c,d

Let me know how to take care of this max condition ?

2)
ANS will be 93C3-4C1*47C3
@bs0409 said:
BELGIS=142857SO ANS=75+142857+1425+47+2485=146889
any approach?
@anuragu79 said:
1)In how many ways can 12 balls be divided among 3 people such each can get a max of 6 balls .2) a +b +c+ d = 90 , a,b,c,d Let me know how to take care of this max condition ?
(6 - a) + (6 - b) + (6 - c) = 12

a + b + c = 6
=> number of soln. = 28
@joyjitpal said:
any approach?
No approach..........Only experience....:p:p
Find the sum of all the 3 digit numbers formed with the digits 2,3,4,5.Repetitions are not allowed.
If 999abc= def132,
then what will be a+b+c+d+e+f ?
@jain4444 said:
(6 - a) + (6 - b) + (6 - c) = 12a + b + c = 6 => number of soln. = 28
I thought of the same method..but it betrayed me in 2nd sum...
When I try the same, it gets me back to the original equation..So, probably the method we are deploying is true in this particular case only..
Pls explain 2nd sum if u can
@bs0409 said:
No approach..........Only experience....Find the sum of all the 3 digit numbers formed with the digits 2,3,4,5.Repetitions are not allowed.
9324
@bs0409 said:
BELGIS=142857SO ANS=75+142857+1425+47+2485=146889
@joyjitpal said:
any approach?

6*10^3*BEL + 6*GIS = 10^3*GIS + BEL

5999*BEL = 994*GIS

BEL = 142
GIS = 857

value = 75 + 142857 + 1425 + 47 + 2485 = 146889

@bs0409 said:
2) ANS will be 93C3-4C1*47C3
Please elaborate a bit...:)
@ani4588 said:
43?
Pls post d approach...43 is ryt...
@Abhinav.kumar said:
If 999abc= def132,
then what will be a+b+c+d+e+f ?
999*868=867132
ANS=43
@bs0409 said:
No approach..........Only experience....Find the sum of all the 3 digit numbers formed with the digits 2,3,4,5.Repetitions are not allowed.
3!*(2 + 3 + 4 + 5)(111) = 9324 ?
@bs0409 said:
999*868=867132ANS=43
Pls elaborate..m nt gtng...