Answer:
The speed of boat on its speedometer is:
x = 35 mph
Step-by-step explanation:
Let the speed of water in still water = x
Speed of stream = 5 mph
Speed of boat upstream = (x - 5) mph
Time taken for upstream = 2 hours
Speed of boat downstream = (x + 5) mph
Time taken for downstream = 1.5 hours
Distance the boat traveled upstream = D₁
Distance the boat traveled downstream = D₂
Both distances are equal.
We know that Distance = Speed · Time
Substitute in given equation:
D₁ = D₂
v₁t₁ = v₂t₂
(x - 5)(2) = (x + 5)(1.5)
2x - 10 = 1.5x + 7.5
2x - 1.5x = 7.5 + 10
0.5x = 17.5
x = 35 mph
