Why do this problem?
gives practice in calculating with fractions and encourages different ways of representing and recording.
What could you draw or write down to help you?
Have you tried working backwards?
What fraction of the total time for the cinema and shopping is the $10$ minutes of shopping?
So how long did they spend in total watching the film and shopping?
is a similar problem which might make a good follow-up activity.
would be a good problem to try first if children find calculating with fractions difficult.