1. Suppose that while one worker was digging the trench, the other workers did not rest but continued to dig the trench for the next pipes. By the time the fourth worker finished digging 50 m, an additional $4 \cdot \frac{3}{4} \cdot 50=150 \mathrm{m}$
of trench had been dug. Therefore, the entire team had dug $150 \mathrm{m}+50 \mathrm{m}=200 \mathrm{m}$.
Answer: $200 \mathrm{m}$.





















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