Official Quant thread for CAT 2013

MBA CAT 2024
12601
@ravi.theja said:
@insane.vodka ans nahi pata bhai sry method pucho..ll discuss
Probability concept hein...I cant do it...no probability :(
12602
@sahil.oberoi said:
Method jugaadu hai par badiya hai....!!!!!!!!Thanks...bht basic questns puch rha hun...abi start ki hai prep...working rite now!!!!!!!!
jugaadu rahegi...par if praticed well will minimize time in money and coins waala problems...even helps in TSD...
12603
@Highway66 u went frm optns 😃 any standard method for these kind of problems??
12604
@ravi.theja nai yar.. i thought to keep prob as close as 0.9.. so just went by options.. otherwise too much cumbersome to go from n=1 to the end.. n=8 wasnt fitting so went for n=7..
12605
@sahil.oberoi 105?
x+y/2+z/4=210
x:y:z=5:6:8=k (say)
10k/18=210
k=21*18
x=5k/18=105
12606

@Highway66 said:
@sahil.oberoi 105?x+y/2+z/4=210x:y:z=5:6:8=k (say)10k/18=210k=21*18x=5k/18=105
10K/18 kaise aya yaa....???
Generally x : y : z ko kaise interpret karte hain..

12607
@sahil.oberoi substitue x, y and z as 5k/18, 6k/18, 8k/18 in main equation. solve to get k
12608
@ravi.theja

Should be 7..I dnt noe why its not in the option..

Let there be 'n' shots at the bridge..

Given, Probability of bomb hitting bridge=1/2

Now, Let the probabilities of 1 out of n shot hitting the bridge be P(n), and so on..

Thus, 1 = P(0) + P(1) + P(2) + ..... + P(n)

However, the target would be destroyed in 2 hits..

Thus, P = P(2) + P(3) + .... + P(n) [where, P = Probability of bridge getting destroyed]

=>1 = P(0) + P(1) + P

=> 1 -P =P(0) + P(1)

=>1-0.9 >= (nC0 + nC1)*(1/2^n)

=> 0.1 >= (1 + n)*(1/2^n)...(i)

At n=6, RHS= 0.109

At n=7, RHS = 0.0625..

Thus, a minimum of 7 bombs required to completely destroy the bridge..
12609
What is the minimum number of square marble tiles required to tile a floor of length 2 metres 56 cm and width 3 metres 36 cm?
336
256
748
1356
12610
@ravi.theja All the Sqares should be of same size ?
12611
@ashishgupta144 yes 😃 :)

12612

256 - 2^8

336 - 2^4 * 3 * 7

GCD(Side of each square) - 2^4

Area of each square tile - 16*16 = 256

Number of tiles = (256*336) / 256 = 336

12613
@ravi.theja said:
What is the minimum number of square marble tiles required to tile a floor of length 2 metres 56 cm and width 3 metres 36 cm?
336
256
748
1356

256 - 2^8

336 - 2^4 * 3 * 7

GCD(Side of each square) - 2^4

Area of each square tile - 16*16 = 256

Number of tiles = (256*336) / 256 = 336

12614
@ravi.theja OA 336 ?
12615
@ashishgupta144 haan bhai OA:336
12616
N=345345345....upto 300 digits. What is the remainder when N is divided by 999? Also find the remainder when N is divided by 1001.
12617
@ravi.theja said:
N=345345345....upto 300 digits. What is the remainder when N is divided by 999? Also find the remainder when N is divided by 1001.
N=345*10^297......+345*10^3+345
10^3 mod 999=1
10^3 mod 1001=-1
N mod 999=345+345+345+... 100 times=34500 mod 999=534?
N mod 1001=-345+345-345+345.......+345=0
12618
@ravi.theja said:
N=345345345....upto 300 digits. What is the remainder when N is divided by 999? Also find the remainder when N is divided by 1001.

Remainder when divided by 999

345*10^297+345^10^294+.......345*10^3+345

10^3/999 =1

345(1+1+....100 times) = 34500/999 = 534


Remainder when divided by 1001

345(-1+1-1+!...100 times) = 0
12619
Find the remainder when 126*128*....*188 is divided by 29!
12620
find remainder when 21^3 + 23^3 + 25^3 + 27^3 is divided by 96.