A: 163

Solution: All of these numbers are perfect squares but have been reversed. The numbers shown (albeit backwards are 144, 169, 225, 256, 289, 324 are 12 squared through 18 squared). Therefore the next number is 19^2 (361) reversed.

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Place numbers (1 to 9) in the blank circles. Each number can only be used once.

Each sector’s number is equal to the sum of the three numbers next to its sector. Find the missing numbers.

Q: A snail is at the bottom of a 12-foot well. She climbs up 3 feet during the day, but slides back 2 feet each night. How many days will it take her to get out of the well?

A: 10 days
After 5 days, she is 5 feet from the bottom. After 6 days, she is 6 feet from the bottom. It will take her less than 12 days.
At the end of the 9th day, she will be 9 feet from the bottom so on the 10th day when she climbs up 3 feet, she will reach the top!