hi bro !!
please explain the trick !!!
what is the concept ?
2 frnds after a long time decided to meet at a particular coffee shop between 5:00 pm to 6:00 pm on a specified day.they also decided that the person whho comes earlier will not wait for the second person for more than 10mins. find the probability that they meet.
11/36 is the answer.
The trick is that |x-y|<10 has to be plotted on a square with origin 0 and length of each side 60 units!
Could u understand the explanation?
see if u look closely, the idea is to find probability that |x-y|<10/60=1/6 hrs right (their time difference is less than 10 minutes.)
Suppose that the first person comes at time x
and the 2nd person comes at time y
it is also known that 5<x<6 and 5<y<6
plot of x,y will be in a square of size 1.
and their in that square we plot |x-y|<1/6
this will give the favorable area! hence teh solution!
The favorable area will be 1-2.1/2.(5/6)2 = 1 - 25/36
=11/36
in this image the two lines are the lines between which they can meet.
so the shaded region gives the time they will meet.
x axis is the time when 1st person arrives
y axis is the time when 2nd person arrives.
i hope it is clear now!