Ram and Rahim agree to meet at a place between 4 P.M. to 6 P.M. The first one to come waits for 24 m

M4maths Previous Puzzles

22 Jul 2016 Probability of meeting?

Ram and Rahim agree to meet at a place between 4 P.M. to 6 P.M. The first one to come waits for 24 minutes and then leaves. If the time of their arrival are independent and at random then what is the probability of a meeting between Ram and Rahim.

OPtion

1) 16/25
2) 1/25
3) 2/3
4) 1/5
5) 4/5
6) 3/5
7) 1/2
8) 9/25
9) 1/3
10)1/120

Solution

Total interval = 120 minutes
There are two persons hence total areal time interval = 120*120
Meeting interval = 24 minutes
Interval in which meeting is not possible = 96 minutes
There are two persons hence the total areal time interval for cancellation of meeting = 96*96
Total areal time interval for meeting = 120*120 – 96*96
Probability = (120*120 – 96*96)/ 120*120
= 9/25

Correct Option: 8 Best Solution (2)

Sharfras Ahamed   8 years AGO

Because probability for any one meet is 1/5
Then by using the formula w1+w2-(w1)^2/2-(w2)^2

Like? Yes (3) | No (2)  

ANUJ KUMAR   8 years AGO

use formula
(2n-1)/(n^2)
where n is no of partitions frm 4 to 6 pm by 24 min.

Like? Yes (4) | No (6)