To solve this question, the user needs to know basic arithmetic, the units of measurement, and the concept of relative motion.
First, we need to determine how many feet are in three rungs of the ladder. We know that the ladder is 10 feet long and there is one foot between each rung, so there are 9 feet of actual ladder. Since there are two spaces between the three rungs, we add 2 feet to the 9 feet of ladder to get a total of 11 feet that need to be covered by the rising tide.
Next, we need to determine how long it will take for the tide to rise 11 feet. Since the tide rises at a rate of 6 inches per hour, or 0.5 feet per hour, we can set up a proportion to solve for the time it will take:
0.5 feet/hour = x hours/11 feet
Solving for x, we get:
x = (11 feet)/(0.5 feet/hour) = 22 hours
Therefore, it will take 22 hours for the tide to rise 11 feet and cover three rungs of the ladder.
Now, let's go through each option and explain why it is right or wrong:
A. 1 hour: This option is incorrect because it is not enough time for the tide to rise 11 feet and cover three rungs of the ladder.
B. 1.5 hours: This option is incorrect because it is not enough time for the tide to rise 11 feet and cover three rungs of the ladder.
C. 2 hours: This option is incorrect because it is not enough time for the tide to rise 11 feet and cover three rungs of the ladder.
D. None of the above: This option is correct. None of the given options is enough time for the tide to rise 11 feet and cover three rungs of the ladder.
The Answer is: D. None of the above.