Look at this bar-line chart which shows how many times Jack cycled to school each week over a 20 week period.
On week 1, Jack cycles to school twice.
On week 2, Jack cycles to school five times.
On week 3, Jack doesn't cycle to school.
During how many weeks, did Jack cycle to school three times?
If we look at the bar-line chart, we can see that Jack cycled to school three times during weeks 5, 6, 10 and 15.