How many digits?

Question

How many 3-digit numbers can be formed using the digits 0, 1, and 2? Repeated digits are allowed.

Answer 1

0 is not a leading digit; for example 21 is not written as 021

you have 2 digits to choose from for the first digit, 3 to choose from for the second digit, and 3 to choose from for the third digit

2*3*3=18 3-digit numbers can be formed

 

100

101

102

110

111

112

120

121

122

200

201

202

210

211

212

220

221

222

Answer 2

3³ = 27

:)