This caught my attention Stolyar.
Seven workers from the first group have to pan out 100 tons of auriferous ore. The second group consists of four workers, two apprentices, and one master who work 1/3 and 1┬╜ as fast as does a worker accordingly. The second group has to pan out the same pile of ore. Find a ratio of the time that the first group needs to have the work done to the time that the second group needs.
Does the work done equal 100 ores?
Yes, the work equals to panning out 100 ton. But since the work is the same for both groups, you can equal it to 1.