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Rule of Sum and Rule of Product

Rule of Sum and Rule of Product Warmup

A palindrome is a number that reads the same forwards and backwards (like 747). Which of the following numbers is a palindrome?

100 101 102 All of the above

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by Brilliant Staff

How many 3-digit palindromes are there? (Note: The first digit of a 3-digit number must be nonzero.)

Fewer than 100 Exactly 100 More than 100

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If $A$ is the number of 3-digit palindromes and $B$ is the number of 4-digit palindromes, which is greater?

A

B

A

and

B

are equal

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How many 3-digit palindromes are there where the middle digit is larger than the outer digits (like 121)?

Fewer than 45 Exactly 45 More than 45

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How many 3-digit palindromes are there where the middle digit is the same as the leading digit?

Fewer than 10 Exactly 10 More than 10

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