ISI 2009 ME 1

[urvashi]

How do we do question 9 i somehow always get these type of qstns wrong if someone could give a detailed explanation thanx

[urvashi]

Very sorry q 12 pls the prob of meeting

[duck]

Hi :)

Think of time interval 4pm to 5 pm as interval [0,1]
{For instance: 4.15 pm is like 1/4; 4.30 pm = 1/2;  4.45 pm is equivalent to 3/4 and 5 pm is equivalent to 1}

Let, X - A's arrival time ~ U[0,1]
and Y - B's arrival time ~ U[0,1]

A and B agree to meet not more than 15 mins.. So, its like finding the following expression:

Pr(|X -Y| < 1/4) [ shaded region in the graph]
 = 1 - (sum of two triangles)
 = 1 - 1/2*3/4*3/4 - 1/2*3/4*3/4
 = 7/16