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# Official Quant Thread for CAT 2011 [Part 8]

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Six couples together went for a picnic .Among them the husbands are - Amit,Sandeep,Rahul,Bobby and Mukesh .and the wives are - Madhuri, Jaya ,Sridevi ,Rani ,Tanuja ,Sharmila .
!!

6 ladies and only 5 gentlemen, how do they make 6 couples ?
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is it 382,
first round-2 minutes
second round - 4 minutes
nth round 2^n minutes
6th round 64 minutes
we need to find number of times they meed in 7th and 8th round
during 7th round they would meet 127 times
and 8th roung they would meet 255 times
127+255=382

whats the OA

OA is 382
• 1 Like
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IIFT-2009 paper

1/1.2.3 + 1/3.4.5 + 1/5.6.7 + ......................

M Stucked after partial fractions

1/2[1/(2n-1) - 1/n + 1/(2n+1)]

Plz suggest upon

S = 1/1.2.3 + 1/3.4.5 + .....
S = Summation of {1/2 [ 1/(2n-1) - 1/n + 1/(2n+1)] }

We know that Integration of dx/x = ln(x)

S = 1/2 [ (1/2) * ln(2n-1) - ln (n) + (1/2) * ln(2n+1) ] , where n ~ infinity

S = 1/4 { ln [(2n-1)*(2n+1)/n^2] }
S = 1/4 [ln (4 -1/n^2) ] , where n ~ infinity

Therefore S = (1/4) * ln (4) = (2.303/4) * (log 4) = 0.346 ~ 0.35
Smoothest seas do not make tough sailors
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Two motorists Anil and Sunil are practicing with two different sports cars: Ferrari and Maclarun, on the circular racing track, for the car racing tournament to be held next month. Both Anil and Sunil start from the same point on the circular track. Anil completes one round of the track in 1 minute and Sunil takes 2 minutes to complete a round. While Anil maintains same speed for all the rounds, Sunil halves his speed after the completion of each round. How many times Anil and Sunil will meet

between the 6th round and 9th round of Sunil (6th and 9th round is excluded)? Assume that the speed of Sunil remains steady throughout each round and changes only after the completion of that round.

260
347
382
None of these
Plz share the approach as well.

is it 382,
first round-2 minutes
second round - 4 minutes
nth round 2^n minutes
6th round 64 minutes
we need to find number of times they meed in 7th and 8th round
during 7th round they would meet 127 times
and 8th roung they would meet 255 times
127+255=382

whats the OA
• 1 Like
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Two motorists Anil and Sunil are practicing with two different sports cars: Ferrari and Maclarun, on the circular racing track, for the car racing tournament to be held next month. Both Anil and Sunil start from the same point on the circular track. Anil completes one round of the track in 1 minute and Sunil takes 2 minutes to complete a round. While Anil maintains same speed for all the rounds, Sunil halves his speed after the completion of each round. How many times Anil and Sunil will meet
between the 6th round and 9th round of Sunil (6th and 9th round is excluded)? Assume that the speed of Sunil remains steady throughout each round and changes only after the completion of that round.

260
347
382
None of these
Plz share the approach as well.

speed is halved so time is doubled
7th round takes 2^7 mins
8th round takes 2^8 mins
2^7+2^8=384
YNWA!! Liverpool till Death!!!!!!!!!!! CAT 2013 99.54
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Six couples together went for a picnic .Among them the husbands are - Amir,Sandeep,pradeep ,Rahul,Bobby and Mukesh .and the wives are - Madhuri, Jaya ,Sridevi ,Rani ,Tanuja ,Sharmila .
In the picnic, while they were playing a game ,all of them divided into six teams -Coconut, Jackfruit,Banana ,Orange ,Mango and Pineapple .No person was in the same team as his/ her spouse ,also each group consists of exactly two persons .We know the following information about them ,

(1)Amir and Sandeep's wife were in the same team .Rahul was in the team Coconut but neither Tanuja nor Sridevi was in that team .
(2) Pradeep , whose spouse was in team Orange, and Tanuja were in the same team
(3)Sandeep is the husband of Sharmila ,who was in the team Banana
(4)Mukesh and Rani were in the team Jackfruit and none of their spouses was in Orange or Coconut team
(5)Jaya and Sridevi 's husband were in the same team,Sridevi and jaya's husband were in the same team ,and one of these groups was pineapple

(6) Madhuri's spouse was in the team Mango

Q1)who is the husband of Sridevi ??
(1) rahul (2) bobby (3)pradeep (4)amir (5) cannot be determined

Q2) who is the wife of mukesh ??
(1) Madhuri (2)Rani (3) Sridevi (4)Jaya (5) Tanuja

Q3) who was in the same team as bobby's spouse ??

(1) rahul (2) Amir (3) pradeep (4) Mukesh (5) bobby

plzz post the approach !!

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Two motorists Anil and Sunil are practicing with two different sports cars: Ferrari and Maclarun, on the circular racing track, for the car racing tournament to be held next month. Both Anil and Sunil start from the same point on the circular track. Anil completes one round of the track in 1 minute and Sunil takes 2 minutes to complete a round. While Anil maintains same speed for all the rounds, Sunil halves his speed after the completion of each round. How many times Anil and Sunil will meet
between the 6th round and 9th round of Sunil (6th and 9th round is excluded)? Assume that the speed of Sunil remains steady throughout each round and changes only after the completion of that round.

260
347
382
None of these
Plz share the approach as well.
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Subhashdec2 Says
What are the options???

Method batao yaar options kya karna
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IIFT-2009 paper

1/1.2.3 + 1/3.4.5 + 1/5.6.7 + ......................

M Stucked after partial fractions

1/2

Plz suggest upon

if i remember correctly, this question had options using e and logs involved, so
going by partial fractions are probably not the way to go ..s

summing first 3 terms ..
1/1.2.3 + 1/3.4.5 + 1/5.6.7 = 1/6+1/60+1/210 = .16 + .016 +.004 ~ .18
next term is 1/7.8.9 ~ 1/504 ~ .002 can be neglected ..

EDITING .. here are the options ..

e^2 -1 ~ 2.7^2 - 1 -- nowhere close

ln 2 -1 -- .693 - 1 .. negative !

2log2 - 1 = 2*.301 -1 .. negative !

option D - none of these. .

me vs me -- how would you approach this with these options ?

aur koi method ho toh batao yaar .. i admit that though this is a very kaam chalau method .. i find myself doing this in every series question of this type

Rank 16 to 456 : 440 V jhatka :P
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IIFT-2009 paper

1/1.2.3 + 1/3.4.5 + 1/5.6.7 + ......................

M Stucked after partial fractions

1/2

Plz suggest upon

Such questions are best solved using options,
please provide options and I will try and tell you a way to solve such questions.
Gaurav Rohella | XIMB-PGDM(2012-14) | Core Member Illuminatix | Media and PR Cell, XIMB
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9*(ab)*(cde) =abcde
where ab 2 dig no
cde 3 dig no
abcde 5 dig no
Find ab and cde

My take is ab = 14 and cde = 112

9 * (ab) * (cde) = abcde
=> 9 * (ab) * (cde) = 1000ab + cde

We can observe that 9*b*e gives 'e' as the unit digit which means that either 'b' is 9 or 'b' is 4

Case 1: b = 9
We have 9 * (10a+9) * (cde) = 1000(10a+9) + cde

we can rearrange to form the equation as
(cde) = (1000a + 900)/(9a+8 )
for any value of 'a' R.H.S is not an integer value.....Hence b != 9

Case 2: b = 4
We have 9 * (10a + 4) *(cde) = 1000(10a+4) + cde

We can rearrange to form the equation as:
cde = (2000a + 800)/(18a+7)
For a = 1 cde =112

Now Verify
We found out that a = 1, b = 4 and cde =112
9*(14)*(112) = 14112......Hence proved
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Smoothest seas do not make tough sailors
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Neetujain1987 Says
Still I didnt get whese 2 traingle are similar.

apd=90-a

in triangle apx
x is the point of intersection of dp and ar
xpa=apd=90-a
xap=rap=a

in triangle bar
rap=a
bra=90-a

YNWA!! Liverpool till Death!!!!!!!!!!! CAT 2013 99.54
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Subhashdec2 Says

Still I didnt get whese 2 traingle are similar.
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IIFT-2009 paper

1/1.2.3 + 1/3.4.5 + 1/5.6.7 + ......................

M Stucked after partial fractions

1/2

Plz suggest upon

What are the options???
YNWA!! Liverpool till Death!!!!!!!!!!! CAT 2013 99.54
Commenting on this post has been disabled.

IIFT-2009 paper

1/1.2.3 + 1/3.4.5 + 1/5.6.7 + ......................

M Stucked after partial fractions

1/2

Plz suggest upon

Commenting on this post has been disabled.