Hi - could someone explain to me how you would solve this algebraically and using the “relative speed” method?
Marla: 32 \text{ laps} \rightarrow 60 \text{ minutes} \implies 1 \text{ laps} \rightarrow \frac{15}{8} \text{ minutes}
Nick: 12 \text{ laps} \rightarrow 60 \text{ minutes} \implies 1 \text{ laps} \rightarrow 5 \text{ minutes}
v = \frac{\text{distance}}{\text{time}}
v_{Marla} = \frac{1\text{ lap}}{\frac{15}{8} \text{minutes}}
v_{Nick} = \frac{1\text{ lap}}{5 \text{ minutes}}
v_{Marla} - v_{Nick} = \frac{8}{15} - \frac{1}{5} = \frac{5}{15} = \frac{1}{3}
Now it’s given that distance is 4 laps. Therefore
v = \frac{d}{t} \implies \frac{1}{3} = \frac{4}{x}
x = 12