21ne1 ??
16 Answers
62Question 3 is a small flavour of Decision Theory but dont go into that thinking it is easy!!!
let him hit on bush 1 n times and bush 2 (10-n) times
prob that it is behind bush A is 4/5
probability of it being hit is
(4/5)(1/2)n+ 1/5(1/2)10-n
you have to maximize this
it is
{(1/2)n-2+ (1/2)10-n} 1/2
This is to be maximised.. that I am sure you can ;)
that will be when n=6 i think!
1////\\\\\
/ →horizontal bar \ →vertical bar ... u will notice that their arrangement will give u the number of paths ..
arrange 4 horizontal and 5 vertical bars 9 !/ 4!5! = 126 total ways ...
out of this the no. of ways he can reach 2,3 and from 2,3 to 4,5 ... 5!/2!3! * 4!/2!2!= 60 .. so 60/126 = 10/21 .. B
21par y no of goli / bush proportnal to P of dear hiding in bush
62second question means that the probability of getting a red ball is atleast "even" *(Half) (It is a phrease used for justifying equal odds!)