GCSE Maths Practice: inverse-proportion

\( \begin{array}{l}\text{Which examples show inverse proportion between workers and time?}\end{array} \)

Select all correct options:

\( \text{4 workers take 10 hours, 8 workers take 5 hours} \) \( \text{3 workers take 15 hours, 5 workers take 9 hours} \) \( \text{6 workers take 12 hours, 3 workers take 24 hours} \) \( \text{5 workers take 20 hours, 10 workers take 20 hours} \)