@YouMadFellow said:I already did, here it is :www.pagalguy.com/forums/chit-c...Not much, but enough to get you started ..
variance me n-1 kab aata tha denominator me..sample lete hain tab na ..not in population ?
@anupam001 Haan. But itna complex funda nahi aana chahiye CAT mein. 4-5 nos ka variance poochenge to usme n hi ayega.
@anupam001 said:variance me n-1 kab aata tha denominator me..sample lete hain tab na ..not in population ?
Yaar.. mujhe bhi yeh clear nahi hai.. All I know is.. (n-1) wala is not be considered in CAT :P.. tum hi bata do..
@YouMadFellow said:Yaar.. mujhe bhi yeh clear nahi hai.. All I know is.. (n-1) wala is not be considered in CAT .. tum hi bata do..
mera doubt tha to @RoadKill ke upar waale post ke according hoga sab :P
@anupam001 said:mera doubt tha to @RoadKill ke upar waale post ke according hoga sab
Wo statistics ka banda hai 😃 .. Use nahi pata hoga to kise pata hoga? Waise @RoadKill .. reason kya hai ? Kyun (n-1) ? .. something related to probability function ?
@YouMadFellow Population ke ek ek item ka agar value pata hai, then use N for variance. But if you have a sample out of that population, and are using this sample to estimate the entire population's variance/sd, then use n-1. Here, the sample variance/sd is an "indicator" of the population variance/sd, and the derivation behind using n-1 instead of n comes from a concept of making the indicator unbiased over the long term. Detailed derivation yaad nahi, and in any case itna nahi poochenge.
Also, this applies only to variance/sd. When using a sample to estimate "mean" of the population, then use n only.
What is the day on 1st January, 1 AD ?? Monday or Sunday ?
Is this fine ?
1 AD's calendar should match 1601's calendar,which should match 2001's calendar.. -> Monday ?
@YouMadFellow As discussed, Jesus did not start the Lord's work by first taking a day off. 😛 1st Jan, 1 AD was a Monday.
@YouMadFellow said:Time and Distance, Work:1. Average speed = Total distance/ Total time2. Relative speed-> opposite direction = v1 + v2, same direction = |v1-v2|3. Circular motion (speeds a,b , track length L, starting at the same point):a) If ratio of speeds is m:n, they meet at (m+n) distinct points, if opposite direction, and they meet at |m-n| distinct points, if same direction. (The points are distributed symmetrically)b) First meeting time = L/(a+b) or L/(|a-b|) respectivelyc) The sum of the distances travelled by the two, between any two meeting points, when travelling in opposite direction is Ld) The difference of the distances travelled by the two, between any two meeting points, when travelling in same direction is Le) Clocks concept can be clubbed with this: Hour hand moves at (1/2) degree per minute, Minute hand moves at 6 degree/minute. We can use relative speed concept to find out angle between them etc. Detailed Clocks in another post.4. Linear motion (speeds a,b , track length L, starting at opposite ends):If ratio of the speeds is not more than 1.5,a) they meet at m distinct points where m>n and m:n is the ratio of the speeds, but the sequence of the points repeats after every (m+n) meetings.b) the sum of the distances travelled between each meeting point = 2*LIf ratio > 1.5, brute force method is the only method I think.5. Man Days/ Man hours concepts:For a particular work to be done, the man days required to complete the work is the same or varies in direct proportional to the work to be doneEx: 5 mandays = 5 men 1 day OR 1 man 5 daysSo, in general N*D*H/W = constant,where N = number of men, D = number of days, H = hours worked per day, and W is the work to be done. W is generally taken as 1, or any other suitable quantity.Money is shared between the workers in the proportion of their work done during the time period.Thanks to All SB guys for all the concepts above !
Ratio should be less than 2....???
0
@michael88 said:Ratio should be less than 2....???
No, I think it's 1.5 .. If in doubt, solve this question:
8 m track AB, Two guys from two ends with speeds in ratio 3:5 .. find their 10th meeting point.
@RoadKill said:@YouMadFellow ye speed ratio
aimcat me bataya tha rat lo...dobara mat poochna :nono:
@RoadKill said:@YouMadFellow ye speed ratio
Maine socha to nahi usko leke, abhi ek axiom leke chal raha hu. But aisi feel aa rahi hai.. ki when write the distance between meeting points in terms of n, v1, v2, L etc.. v1/v2 = 1.5 pe ek end point pe meet hoga, and that is the boundary case, uske baad there will be two meetings during that 2L distance, I think...
Also, ek extreme case leke feel aa rahi hai.. jab ratio is 1:10, tab bechara slow wala utna chal hi payega, aur tez wala aage usko pakad lega. Isliye kal wo wala question pucha tha maine.. 8m, 3:5 speed etc..(usme ratio is more than 1.5)
Calendar sums mai do we assume 1 jan 2001 to be Monday even if not given in question? 
Find max of function - f(x) = x+y
x
@ankita14 said:Calendar sums mai do we assume 1 jan 2001 to be Monday even if not given in question?
I would say, don't, unless you need to 
..
.. Isse yaad aaya=> Unless p, q means p => neg(q) ??
@YouMadFellow said:Maine socha to nahi usko leke, abhi ek axiom leke chal raha hu. But aisi feel aa rahi hai.. ki when write the distance between meeting points in terms of n, v1, v2, L etc.. v1/v2 = 1.5 pe ek end point pe meet hoga, and that is the boundary case, uske baad there will be two meetings during that 2L distance, I think...Also, ek extreme case leke feel aa rahi hai.. jab ratio is 1:10, tab bechara slow wala utna chal hi payega, aur tez wala aage usko pakad lega. Isliye kal wo wala question pucha tha maine.. 8m, 3:5 speed etc..(usme ratio is more than 1.5)
Thanks...is question mein mushe hamesha doubt rehta tha....aur kisi book mein bhi nhi diya hai.....so limits kabhi nhi maloom thi....Brute force lagata tha max time....
@YouMadFellow said:I would say, don't, unless you need to ..Isse yaad aaya=> Unless p, q means p => neg(q) ??
p unless q => p it not q. :P