Solve Problems Using Systems of Linear Equations
-Julie and Eric row their boat (at a constant speed) 27 miles downstream for 3 hours, helped by the current. Rowing at the same rate, the trip back against the current takes 9 hours. Find the rate of the current.
A) $3 \mathrm { mph }$
B) $6 \mathrm { mph }$
C) $4 \mathrm { mph }$
D) $2.5 \mathrm { mph }$

Question

Quizplus · Accepted Answer

The downstream speed is the boat speed plus the current speed, and the upstream speed is the boat speed minus the current speed. Using the distances and times given, we can set up two equations: $27 = 3(b+c)$ and $27 = 9(b-c)$. Solving these equations simultaneously gives the current speed as 3 mph.

Solve Problems Using Systems of Linear Equations -Julie and Eric 3mph3 \mathrm { mph }3mph

Solve Problems Using Systems of Linear Equations
-Julie and Eric $3 \mathrm { mph }$