Official Quant thread for CAT 2013

MBA CAT 2022
1661
@maddy2807 said:
In how many ways we can select four cards of different suits & different denominations from a deck of 52 cards??Confusion is between : 52 X 36 X 22 X 10and 13 X 12 X 11 X 10@krum
sir, my take would be 13*12*11*10
1662

_a_b_c_

w x y z

w+x+y+z=5 where w,x,y,z>=0
no of soln to ablv eqtn
(8)C(3)
1663

The average marks of those there are two taps t1 and t2 and two buckets p1 and p2. T1 takes 12 hours more to fill p2 than p1. T2 takes 24 hours more to fill p2 than p1. How many hours will both take combined to fill p2 than p1?

1664
How many natural nos having at most 5 digits have sum of their digits as at most 5?
1665
@maddy2807
13C4 * 4! --> 13X12X11X10 ??
1666
@krum said:
sir, my take would be 13*12*11*10
y???
1667
@rachit_28 said:
How many natural nos having at most 5 digits have sum of their digits as at most 5?
a+b+c+d+e=>a+b+c+d+e+f=5
=>10c5=252

remove case when f=5

so 251
1668
@maddy2807 said:
In how many ways we can select four cards of different suits & different denominations from a deck of 52 cards??Confusion is between : 52 X 36 X 22 X 10and 13 X 12 X 11 X 10@krum
I think if it is well shuffled deck of cards then answer will be 52 X 36 X 22 X 10
And if the cards are already placed in groups according to suits then it will be 13*12*11*10
1669

@Brooklyn said:
4c1*13c1*3c1*12c1*2c1*11c1*1c1*10c1
here u are ordering the cards chosen . we only need the combinations , so divide ur ans.by 4!
@Brooklyn
1670
Sixty
Reply #166505:56 PM, 11 Nov '12
The average marks of those there are two taps t1 and t2 and two buckets p1 and p2. T1 takes 12 hours more to fill p2 than p1. T2 takes 24 hours more to fill p2 than p1. How many more hours will both combined take to fill p2 than p1?
1671
@rubikmath said:
here u are ordering the cards chosen . we only need the combinations , so divide ur ans.by 4!@Brooklyn
how am i ordering can u explain ??
1672
@Brooklyn said:
y???
yaar i think u are considering order as well
1673

selecting 4 cards out of 13 cards is 13c4 --> not 13c1*12c1*11c1*10c1

@Brooklyn
1674
@krum said:
yaar i think u are considering order as well
how am i considering order??

what i did was: choose any suit -> 4c1 then a card from it 13c1 so on
1675
@rubikmath said:
selecting 4 cards out of 13 cards is 13c4 --> not 13c1*12c1*11c1*10c1@Brooklyn
soo wat was ur approach ???
1676
@Brooklyn said:
how am i considering order?? what i did was: choose any suit -> 4c1 then a card from it 13c1 so on
if we go by 52*38*24*10
means first card can be any of the four suits, next can be from any of the 3 suits..
this is ordering right
?
1677
@Brooklyn
select the 4 nos. first --> 13c4
then select the suit for them --> 4!
ans: 13C4*4!
1678
@Sixty said:
Sixty Reply #166505:56 PM, 11 Nov '12The average marks of those there are two taps t1 and t2 and two buckets p1 and p2. T1 takes 12 hours more to fill p2 than p1. T2 takes 24 hours more to fill p2 than p1. How many more hours will both combined take to fill p2 than p1?
Options? Nothing is given for relating T1 and T2.
1679
@krum said:
a+b+c+d+e=>a+b+c+d+e+f=5=>10c5=252remove case when f=5so 251
sorry bhai, isme dummy variable aapne f maan liya, f =5 remove kyu kiya ? :(
1680
@krum said:
if we go by 52*38*24*10means first card can be any of the four suits, next can be from any of the 3 suits..this is ordering right ?
was IMO bt i thnk its not