SOLUTION: How do I solve? A boat can go 20 miles against the wind in the same time that it can go 60 miles with the wind. The wind is blowing at 4 mph. Find the speed of the boat with no

Algebra ->  Test -> SOLUTION: How do I solve? A boat can go 20 miles against the wind in the same time that it can go 60 miles with the wind. The wind is blowing at 4 mph. Find the speed of the boat with no       Log On


   

Question 874240: How do I solve?
A boat can go 20 miles against the wind in the same time that it can go 60 miles with the wind. The wind is blowing at 4 mph. Find the speed of the boat with no wind.
A. 4mph
B. 8 mph
C. 40 mph
D. 80 mph
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
boat speed x mph with no wind
wind speed 4 mph

against wind x - 4 mph
with wind x + 4 mph

Distance against wind 20
Distance with wind 60
Time = same equate the time against with time with current
t=d/r
20 /(x- 4 )= 60 /(x+ 4 )
20 *(x+ 4 )= 60 *(x- 4 )
20 x + 80 = 60 x -240
20 x -60 x = -240 + -80
-40 x = -320
/ -40
x= 8 mph
m.ananth@hotmail.ca