# maths watch

Announcements
1. what is the probability of waiting longer than 15 mins when you arrive randomly a bus stop at which the bus arrives promptly on the hour and on the half hour
2. (Original post by megu1234)
what is the probability of waiting longer than 15 mins when you arrive randomly a bus stop at which the bus arrives promptly on the hour and on the half hour
If the inter arrival time is a constant 30 minute, the expected waiting time for a uniformly randomly arriving passenger is 15 minutes. Therefore the chance of waiting longer than 15 minutes is 50%.
3. (Original post by Igorzycho)
If the inter arrival time is a constant 30 minute, the expected waiting time for a uniformly randomly arriving passenger is 15 minutes. Therefore the chance of waiting longer than 15 minutes is 50%.
thanks

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: February 14, 2018
Today on TSR

### Exam Jam 2018

Join thousands of students this half term

### Solo - A Star Wars Story

Poll

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE