Question

Does this make sense? I need someone to check my answer.

Answer 1

Write out the word problem you created and calculate how fast your friend or family member was traveling in still water. Round your answer to the nearest mph.
Wayne decided he wanted to take his daughter out for an all-day fishing trip. So, they packed up the truck and readied the fishing boat and high tailed it to the nearest doc. To get to his secret fishing spot, Wayne had to sail the boat upstream 60 miles in no less than 6 hours and then back downstream in no less than 3 hours, that is, if they want to make it home for dinner. Determine the speed Wayne must sail in low current waters in order to make it home in time for dinner?

4. Follow the 5 steps below to complete this problem. (4 points)


My Solution:
c = current of river
b = rate of boat
d = s(t) will represent (distance = speed X time)

Upstream: 60 = 6(b-c)
Downstream: 72 = 3(b+c)

There are now two separate equations:
60 = 6b - 6c
and
72 = 3b + 3c

Solve both equations for b:
b = 10 + c
b = 24 - c
Now make both equations equal each other and solve for c:
10 + c = 24 - c
2c = 14
c = 7

The speed of the current was 7 mph
Now, plug the numbers into one of either the original equations to find the speed of the boat in low current water.
I chose the first equation:
b = 10 + c
or
b = 10 + 7
b = 17
The speed of the boat in low current water must remain a consistent 17 mph or more in order for Wayne and his daughter to make it home in time or dinner.

Answer 2

I know it looks long but Its actually all the same problem...