Determine departure time from travel times
SIG (Susquehanna)Data Scientist · Online Assessment
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This question evaluates a candidate's understanding of relative motion, time-distance-rate relationships, algebraic modeling, and quantitative reasoning. Commonly asked in technical interviews for Statistics & Math and Data Scientist roles, it assesses the practical application of setting up and manipulating equations from multi-step word problems rather than purely conceptual theory.
Two friends canoe upstream for 4 hours, then turn and paddle downstream for 5 hours. The next day, they canoe back to their original starting point 23 miles upstream and arrive at 16:00. The river current is a constant 2 mph, and the paddling speed relative to the water is constant (same both days). At what time did they depart on the return trip?
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