Final answer:
Liam can fit 3 tyres to a van in 42 minutes, as it takes him 14 minutes to fit one tyre and the work time divides evenly into three periods of 14 minutes.
Step-by-step explanation:
The question asks us to calculate the number of tyres Liam can fit to a van in a given amount of time. Since it takes Liam 56 minutes to fit 4 tyres, we can calculate the number of tyres he can fit in 42 minutes through a proportional relationship. First, we find out how many minutes it takes to fit one tyre by dividing the total time by the number of tyres:
56 minutes ÷ 4 tyres = 14 minutes per tyre.
Next, we use this information to determine how many tyres Liam can fit in 42 minutes:
42 minutes ÷ 14 minutes per tyre = 3 tyres.
Therefore, during a 42-minute work period, Liam can fit 3 tyres to a van.