Problem
Competing in an endurance race, Shannon cycled for $120 \mathrm{~km}$, then swam for $12 \mathrm{~km}$. Her average cycling speed was five times faster than her average swimming speed. Shannon took nine hours to complete the race. Calculate her average swimming speed. (5 marks)
Solution
Step 1 ：Let x be Shannon's average swimming speed, then her average cycling speed is 5x. Set up the equation: \(\frac{120}{5x} + \frac{12}{x} = 9\)
Step 2 ：Solve for x: \(x = 4\)
Step 3 ：\(\boxed{4}\)
