Question

A palindrome is a number that reads the same forward and backward. For example, 2442 and 111 are palindromes. If 5-digit palindromes are formed using one or more of the digits 1, 2, and 3, how many such palindromes are possible?

a) 12
b) 15
c) 18
d) 24
e) 27

Answer 1

The correct option is e) 27.

Explanation:

Consider the provided information.

We need to find how many palindromes are possible If 5-digit palindromes are formed using one or more of the digits 1, 2, and 3,

The number should be in the form of XYZYX

Now for the first digit we have 3 choices, for second digit we also have 3 choices, for third digit we also have 3 choices but for fourth and fifth digit we have only one choice.

Therefore the number of possible palindromes are:

3 × 3 × 3 × 1 × 1 = 27

Hence, the correct option is e) 27.