Official Quant thread for CAT 2013

@catahead said:
| 12 / (x-15) | >5=> | 1/(x-15) | > 5/12=> | x - 15 | => -12/5 => 15-12/5 => 12.6 SO max value = 17 and min value = 13
with catahead we dont even need to explain!!
@raopradeep said:
find the complete range of x for which (x^2+x+1)^2x (-inf,0)(0, inf)(1 ,inf)(-inf ,-1)
taking log both sides, 2xlog(x^2 + x + 1) x
however inside log , x^2 +x + 1 cannot be 0, x cannot be -1. hence option 4

@raopradeep said:
what is the difference between the largest and smallest integer that satisfies the inequality|12/(x-15)|>54362
x>12.6 and x
diff=17-13=4

@raopradeep said:
@ishu1991 bro answer is in integer not in fraction oa is 4
yar i missed the integer part its 17-13=4
@DeAdLy said:
arey vaibhav glat answer hai yar...its not correct
for simple interest, the amount borrowed is the principal for the entire period of borrowing.
Courtesy: Arun sharma. ( first page of interest chapter)

Main to hamesha yahi use karta hun....answer bhi correct aa hi jaate hain.... but still its better if we confirm it from someone else.

@ankittripathi said:
for simple interest, the amount borrowed is the principal for the entire period of borrowing.Courtesy: Arun sharma. ( first page of interest chapter)Main to hamesha yahi use karta hun....answer bhi correct aa hi jaate hain.... but still its better if we confirm it from someone else.
Yar formula to yahi hai..everyone here knows that!!! but better to get confirmed because approach matters!!
@pratskool said:
it should be the number of 3 digit factors of the difference of two numbers...13914 - 12714 = 1200100,120,150,200,240,480,600.... 7 numbers?? sorry if i missed any
its 8..u missed out 400
@ankittripathi said:
Please clarify......I have already solved the question and got correct answer.... but would love to know ur approach
A loan of 180000 requires an annual EMI of 17285 per year. So the person is paying a total amount of 17285*21=362991 out of which 180000 is Principal.

So Interest paid=362991-180000=182991 which is obviously less than the given amt of 270900.

Even if interest rate decreases to 7% after some period, the amt of 182991 will only decrease and never increase to 270900......
@bs0409 said:
A loan of 180000 requires an annual EMI of 17285 per year. So the person is paying a total amount of 17285*21=362991 out of which 180000 is Principal.So Interest paid=362991-180000=182991 which is obviously less than the given amt of 270900.Even if interest rate decreases to 7% after some period, the amt of 182991 will only decrease and never increase to 270900......
how did you calculate the EMI?
@bs0409 said:
Not possible.....At flat 7.5%, the EMi comes out to be 17285So total amt. paid=17,285*21=362991So Interest paid=362991-180000=182991But it is given that he paid interest of Rs. 270900....??????????
yar jo bhi hai Q me hai...ans given is 14 years
@techgeek2050 @pratskool Really sorry for such a late reply 😞 was doing some work..
We cannot use that 2D wala formula here because that can only be used if the ratio of speeds is 2 hence we calculate the distances traveled with the conventional method.
I have read the following posts on that page and hope you would have understood why they met 9 times in 100 metres and not 10 times since the 10th meeting would be at "A".
@ishu1991 said:
yar i missed the integer part its 17-13=4
bro thoda explain kar i am getting 19-16 =3

@ankittripathi said:
how did you calculate the EMI?
let EMI be x, then
180000=x/(1+r)+x/(1+r)^2+x/(1+r)^3+.............................+x/(1+r)^21

r=0.075(given)

find x......
If you form a subset of integers chosen from between 1 to 3000, such that no two integers add up to a multiple of nine, what can be the maximum number of elements in the subset.
a.1668 b.1332 c.1333 d.1334
@bs0409 said:
If you form a subset of integers chosen from between 1 to 3000, such that no two integers add up to a multiple of nine, what can be the maximum number of elements in the subset.a.1668 b.1332 c.1333 d.1334
1332
@bs0409 said:
If you form a subset of integers chosen from between 1 to 3000, such that no two integers add up to a multiple of nine, what can be the maximum number of elements in the subset.a.1668 b.1332 c.1333 d.1334
http://www.pagalguy.com/posts/4386671

1334
@bs0409 said:
If you form a subset of integers chosen from between 1 to 3000, such that no two integers add up to a multiple of nine, what can be the maximum number of elements in the subset.a.1668 b.1332 c.1333 d.1334
1,2,3,4...., 10,11,12,13... 4 numbers out of every 9 numbers
3000/9 = 333 + 3/9
so 333*4 + 3 -2 as 1 and 3000 are not included...
1333 not sure though
@bs0409 said:
If you form a subset of integers chosen from between 1 to 3000, such that no two integers add up to a multiple of nine, what can be the maximum number of elements in the subset.a.1668 b.1332 c.1333 d.1334
The number of multiplesof 9 are 333
Now we have to take numbers like 9k+2N where N is an integer so that 2n is even and we will not get another multiples of 9
So 9k+2,9k+4,9K+6.9k+8
So 334,333,333,333
Hence 1333
@bs0409 said:
If you form a subset of integers chosen from between 1 to 3000, such that no two integers add up to a multiple of nine, what can be the maximum number of elements in the subset.a.1668 b.1332 c.1333 d.1334
Nos os the form 9k+1, 9k+2, 9k+3, 9k+4 and 1 no of form 9k would be included.
9k+1 --- 333 nos
9k+2 --- 334 nos
9k+3 --- 333
9k+4 --- 333
Total = 333*3 + 334 + 1 = 1334
@DeAdLy said:
1332
@ScareCrow28 said:
Nos os the form 9k+1, 9k+2, 9k+3, 9k+4 and 1 no of form 9k would be included.9k+1 --- 333 nos9k+2 --- 334 nos9k+3 --- 3339k+4 --- 333Total = 333*3 + 334 + 1 = 1334
@catahead said:
The number of multiplesof 9 are 333Now we have to take numbers like 9k+2N where N is an integer so that 2n is even and we will not get another multiples of 9So 9k+2,9k+4,9K+6.9k+8So 334,333,333,333Hence 1333
@pratskool said:
1,2,3,4...., 10,11,12,13... 4 numbers out of every 9 numbers3000/9 = 333 + 3/9so 333*4 + 3 -2 as 1 and 3000 are not included...1333 not sure though
@Logrhythm said:
OA-1334

0.14141414 is a base 12 number and it can be written as p/q in base 12, then find p and q.