Question

The member of staff lives in Bermondsey in London.

She has to speak at a conference in Birmingham at 10:45am.
It will take her an hour from her home to get to Euston Rail Station, from where she will get a train to Birmingham.
The train journey from Euston to Birmingham is an hour and 10 minutes.
Trains to Birmingham run at the following times: 5 minutes past the hour, 25 minutes past the hour and 45 minutes past the hour.
The meeting venue in Birmingham is a 5-minute walk from the station.
What is the latest time that the member of staff can leave home, if she is to make it on time for the meeting in Birmingham? Show your working.

Answer 1

Explanation:

we could do something like "reverse engineering". starting with the planned outcome we calculate backwards.

she had to speak at 10:45 am

she needs to walk 5 minutes from the station : start latest at 10:40 am

the train journey takes 1 hour 10 minutes. start latest at 9:30 am. since the trains leave at 25 minutes past the hour (and not at 30 minutes past the hour), she needs to take latest the 9:25 train.

it takes her 1 hour to get to the train stain : start latest at 8:25 am.

she needs to leave home latest at 8:25 am