Excavation depth and worker-days

Assume constant individual rates, no interruptions and no change in efficiency when the number of workers or machines changes. For consumption, assume equal constant consumption per person.

Eight workers take \(4\) days to dig \(3\) m of a well, at equal rates. Find

1. the depth dug by \(16\) workers in \(6\) days, and[2]
2. the days needed by \(6\) workers to dig \(1.5\) m.[2]