Answer:4
Step-by-step explanation:
Because it’s the right answer
That's simplied already, unless they want a decimal then it's .6 or something
Let the speed of the boat be x
so going against the current the speed is x-7
going with the current the speed is x+7
let the distance be d
time = distance / speed
time to go against the current = d/(x-7)
time to go with the current = d/(x+7)
time going against the current is 3 times going <span>with the current
</span>
d/(x-7) = 3d/(x+7)
⇒⇒⇒ divide by d
1/(x-7)
= 3/(x+7)
x+7
= 3(x-7)
x+7 = 3x - 21
2x = 28
x = 14
So, the speed of the boat in still water is = 14 mph