A river's current is 4mph. A boat travels 48 miles downstream in the same time it travels 24 miles upstream. Find the speed of the boat.
A) What does the variable stand for?
x stands for the speed of the boat.
B) Write the equation.
24/x - 4 = 48/x + 4
C) Solve.
24/x - 4 = 48/x + 4
24(x + 4) = 48(x - 4)
24x + 96 = 48x - 192
288/24 = 24x/24
mph 12 = x
D) Write the answer in a complete sentence.
The speed of the boat will be 12 miles per hour.
Is this correct?
2 answers
Yes, it is correct. The upstream speed relative to land (8 mph) is half the downstream speed (16 mph), as required.
Thanks
1 answer