City Guilds Model Questions Vol1 2018 Engineering Question 7

In a workshop, three tasks have the following probability (scale 1-5) and severity (scale 1-5) of potential injury: \(\text{Task A}:\) probability 3, severity 4; \(\text{Task B}:\) probability 2, severity 5; \(\text{Task C}:\) probability 4, severity 2. The risk rating is defined as \(\text{rating}=\text{probability}\times\text{severity}\). According to safety policy, a rating \(\ge 12\) requires an engineering control, a rating of 8-11 requires an administrative control, and a rating \(\le 7\) is acceptable with PPE only. If the manager can implement at most one engineering control and one administrative control, and an engineering control reduces a task's rating by 40 % (rounded down to the nearest integer) while an administrative control reduces it by 25 % (rounded down), which tasks should receive each type of control to minimise the total final risk rating? State the final rating for each task after the controls are applied.