The Official CAT 2007 Quant Thread

[mohit_353]

Originally Posted by Krack_CAT

i beg to differ....

with these 9 bags (1,2,4,8,16,32,64,128,127) you can get any value. i.e. from 1 to 382.

Even after all the ramayan and mahabharat, no one has posted the correct option.

I did not get ur point....pls explain......

[1sky_1destiny]

Hey Guys Can Ny1 Tell Me Which Buks Should Be Referred For Preparing Maths, Di, Lr.
As I M Not Able To Join Ny1 Institute...

Plzz Guide Me....for Cat07

[Krack_CAT]

Originally Posted by mohit_353

I did not get ur point....pls explain......

What i meant was, that, only 9 bags are required to get any combination of 382

i.e. 1,2,4,8,16,32,64,128,127

With the bags of these above denominations, we can obtain any value from 1 to 382.

pls explain in detail where i am wrong.. help me (and others who will browse this thread) get my (our) basics right.

[karthikeyantcs]

Originally Posted by Krack_CAT

What i meant was, that, only 9 bags are required to get any combination of 382

i.e. 1,2,4,8,16,32,64,128,127

With the bags of these above denominations, we can obtain any value from 1 to 382.

pls explain in detail where i am wrong.. help me (and others who will browse this thread) get my (our) basics right.

Mohit, Horrible and I have already come to the conclusion that 9 bags is the answer. I think you mistook our posts.

[jaybind]

Originally Posted by 1sky_1destiny

Hey Guys Can Ny1 Tell Me Which Buks Should Be Referred For Preparing Maths, Di, Lr.
As I M Not Able To Join Ny1 Institute...

Plzz Guide Me....for Cat07

hey u can refer arun sharma for quant...its available for di as well...also the career launcher publication book is quite good.u can have a look at these.
will be very helpful

[jaybind]

Originally Posted by mohit_353

hey ...sory 4 wht..we r here to learn from each other..i must be thankful to u guys for taking interest ........

some more stuff......


2.How many 5 digit numbers can be made using 1, 2, 3, 4, 5 such that the digit in the unit

place is greater than the digit in the hundred's place ?

(1) 40 (2) 120 (3) 60 (4) 720





Happy solving.........

the ans for 2nd ques is 60.here is the solution:
case1:take unit place=5 i.e 1 way
then 10th place can be filled in 4 ways,100th place in 3 ways,1000th palce in 2 ways and 10000th place in 1 way.so no of ways=1*4*3*2*1=24
case2:unit place=4,10th place=5 i.e.1 way
100th place can be filled in 3 ways and 1000th in 2 ways and 10000th place in 1 way...
no of ways=6
case3:unit place=4,10th place=any one of (1,2,3)i.e 3 ways
100th place in 2 ways,1000th in 2 and 10000th place in 1 way.
no of ways=12
case 4:unit place=3,10th place=any one of (1,2) i.e 2 ways
100th place in 1 way and 1000th in 2 way and 10000th place in 1 way ...no of ways=4
case5:unit place=3,10th palce=any one of (4,5) i.e 2 ways
100th palce in 2 way,1000th in 2 way and 10000th place in 1 way
no of ways=8
case6:unit place=2
10th place in 3 ways,100th palce in 1 way,1000th in 2 way 10000th place in 1 way
so no of ways=6
so ans=24+6+12+4+8+6=60
i know its quite difficult to understand but then problem is quite complex.any clarifications guys??

[mohit.pasrija]

How many numbers can be formed by using 8,7,5,3,2 such that they are divisible by

125 ? Digits to be used exactly once.

(1) 20 (2) 4 (3) 2 (4) 1

Sol...for a number to be divisible by 125 its last three digits should ve divisible by 125.
so from the above given numbers.
we could have 4 possible numbers i.e.
1.32875
2.23875
3.28375
4.82375

tell me if i m wrong...

[jaybind]

Originally Posted by mohit.pasrija

How many numbers can be formed by using 8,7,5,3,2 such that they are divisible by

125 ? Digits to be used exactly once.

(1) 20 (2) 4 (3) 2 (4) 1

Sol...for a number to be divisible by 125 its last three digits should ve divisible by 125.
so from the above given numbers.
we could have 4 possible numbers i.e.
1.32875
2.23875
3.28375
4.82375

tell me if i m wrong...

hey that looks pretty ok...sohuld be correct..

[jaybind]

Originally Posted by mohit_353

hey ...sory 4 wht..we r here to learn from each other..i must be thankful to u guys for taking interest ........

some more stuff......





4. A number when divided by 3 and 5 gives remainders 1 and 3. What will be the

remainder when the same number is divided by 15?

Happy solving.........

the ans for this will be 13.
the reqired nos will be like 13,28,43 and so on...
which when divided by 15 will give a remainder of 13...
am i right???

[jaybind]

Originally Posted by mohit_353

hey ...sory 4 wht..we r here to learn from each other..i must be thankful to u guys for taking interest ........

some more stuff......



4. A number when divided by 3 and 5 gives remainders 1 and 3. What will be the

remainder when the same number is divided by 15?


Happy solving.........

any other methods for solving this???