Question

A cat is at the bottom of an 18 foot well. Each day it climbs up 3 feet and each night it slides back 2 feet.  How long will it take the cat to get out of the well?

Answer 1

Answer: Let's start by finding out how much distance the cat climbs each day:

Distance climbed during the day = 3 feet

Distance slid back during the night = 2 feet

So, the net distance climbed each day = 3 - 2 = 1 foot

To climb out of the well, the cat needs to climb a total of 18 feet.

Since the cat climbs 1 foot per day, it will take the cat 18 days to climb out of the well.

Explanation:

Answer 2

16 days

Explanation:

This is a tricky question.

If you think of it quickly, you may want to say that it goes up 3 ft each day and down 2 ft each day, so it goes up a net 1 ft per day. Since it must climb 18 ft, it will take 18 days. That is incorrect.

Look at the following table.

Begin Amt Pos. after Amt of Pos. at

Day Pos. of climb climb slide end of night

1 0 3 3 2 1

2 1 3 4 2 2

3 2 3 5 2 3

4 3 3 6 2 4

5 4 3 7 2 5

6 5 3 8 2 6

7 6 3 9 2 7

8 7 3 10 2 8

9 8 3 11 2 9

10 9 3 12 2 10

11 10 3 13 2 11

12 11 3 14 2 12

13 12 3 15 2 13

14 13 3 16 2 14

15 14 3 17 2 15

16 15 3 18

Once it reaches 18 ft high on day 16, it is out of the well.