Quant Tricks and Short cuts

Hi guys,I request you all to share any shortcuts and tricks that you knw in quant, as it will be useful for all of us.Thanks and Regards,

Hi guys,

I request you all to share any shortcuts and tricks that you knw in quant, as it will be useful for all of us.
Thanks and Regards,

Few days back I learnt this.


PICK'S THEOREM
To find no of points in the Region described by the lines x/a+y/b=0 and y>=0
but HCF(a,b)=1 ( a and b both shud be co primes)

No of integer points inside the regions will be = [(a-1)*(b-1) - h]/2

where, h= No of points coinciding with the hypotenuse
when HCF(a,b)=1
h=0

@Aizen @YouMadFellow @Brooklyn @rkshtsurana please share the knowledge...

Sum of perpendicular sides of ryt triangle given area A and semiperimeter S is given by S + A/S

Dind some file attached 😁

Area of rt angled traingle : when incentre =r

circum cetnre =R

A= r(r+2R)

Has come in handy in various places now !!

Positive integral solutions of 1/M + 1/N =1/P is No of factors of p^2.


Ex. 1/M + 1/N = 1/12 will have total of 15 +ve integral solns.

Total no. of integral coordinates inside including boundary |x|+|y|


If the boundary is not included then put n-1 in the eq...

Angle between the hands of clock : 30h-(11/2)m

@pankaj1988 said:
Positive integral solutions of 1/M + 1/N =1/P is No of factors of p^2.
Ex. 1/M + 1/N = 1/12 will have total of 15 +ve integral solns.
bhai isko thoda explain karna... not clear
@pankaj1988 said:
Total no. of integral coordinates inside including boundary |x|+|y|
If the boundary is not included then put n-1 in the eq...
Will it be also applicable for the case, say, |x-a| + |y-b|
@rachit_28 said:
Will it be also applicable for the case, say, |x-a| + |y-b|
i guess it shud be... coz the area remain the same... so as the cordinates...
@maddy2807 Bhai jaise take p=12 so p^2=144 factors will be 2^4 * 3^2 . So the number of factors would be (4+1) * ( 2+1)=15 which is same as no of +ve integral soln of 1/M + 1/N= 1/12.

explanation : Eq can be written as (N-12) (M-12) =144

When done with counting (1,144) (2, 72) (3, 48) (4,36) ( 6,24) (8, 18) (9, 16) (12,12) of which previous 7 can be interchanged so total solns will be 2*7+1.


@rachit_28 said:
Will it be also applicable for the case, say, |x-a| + |y-b|
Bro I am not sure abt it. Though area remains the same but integral coordinates?? Let others throw some light on it......
@pankaj1988 said:
Bro I am not sure abt it. Though area remains the same but integral coordinates?? Let others throw some light on it......
No of integral cordinates also remains the same. in case of |x-a|+|y-b|=p
the only change from |x|+|y|=p is the change in the no of coordinates to (a,b) from (0,0)
Rest thing remains the same
No of Triangle that can be formed with perimeter n will be

[(n+3)^2/48] when n is odd
[n^2/48] when n is even,

[] is the nearest integer function.

@maddy2807

can u elaborate your first trick using the equation say, x/3+y/5=1?
1.sum of all the co-primes of N which are less than N = N/2 * E(N)

2.The probability that an interval broken at n-1 points chosen uniformly at random is broken into pieces which can be rearranged to form an n-gon is :
P =1- (n/2^(n-1)) - aizen sir ka vardan
@billamin said:
@maddy2807
can u elaborate your first trick using the equation say, x/3+y/5=1?
here a=3 and b=5
h=0 as HCF(3,5)=1
so No of integer points= 4