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Question 209399: I need help with the following quetion : A firefighter spraying water on a fire stood on the middle of the ladder. When the smoke became less thick the firefighter moved up 4 rungs. However it got too hot, so the firefighter backed down 6 rungs. Later the firefighter went up 7 rungs and stayed until the fire was out. Then the firefighter climbed the remaining 4 rungs and entered the building. How many rungs did the ladder have ?
I did try to work out this problem using a diagram, but im not sure if the answer is right.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! I need help with the following quetion : A firefighter spraying water on a fire stood on the middle of the ladder. When the smoke became less thick the firefighter moved up 4 rungs. However it got too hot, so the firefighter backed down 6 rungs. Later the firefighter went up 7 rungs and stayed until the fire was out. Then the firefighter climbed the remaining 4 rungs and entered the building. How many rungs did the ladder have ?
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start at rung "h" which is half way up the ladder
Then Add 4; then subtract 6, so he is at h-2
Then Add 7 ; then add 4, so he is at h-2+11 = h+9.
If that is the top of the ladder(?), the bottom
of the ladder is at h-9 so there are 18 + 1 = 19 rungs
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Cheers,
Stan H.
Reply to stanbon@comcast.net
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