1.3 Problem Solving: working backwards activity transcript

Thierry is calculating what time he needs to leave home in order to arrive at his exam on time. He’s using the working backwards technique to decide what time he needs to start getting ready so that he’s not late for his exam.

He needs:

– 30 minutes to take a shower and get dressed

– 30 minutes to have breakfast

– 15 minutes to walk to the bus stop

– 45 minutes for the bus ride

– 10 minutes to walk from the bus stop to the exam hall.

If his exam begins 11.30am, what time should he start getting ready?

A. At 8.30am

B. At 9am

C. At 9.30am

Answer

B. Approximately 9am. It will take Thierry at least two hours and ten minutes to get ready and travel to the exam hall. If he starts getting ready at 9am, he will have enough time to get to the exam hall and maybe even some extra time to chat with his friends before it starts.