Question

How many 3 digit numbers have exactly one digit 2 in the number?

Answer 1

Answer: 225

Step-by-step explanation:

The 3 digits number be _ _ _

Now we cal fill these blanks by 0 ,1,2,3,4,5,6,7,8,9

2 at the unit place

tens place can be fill by = 0,1,3,4,5,6,7,8,9 or 9 choices

Hundred place can be filled by 1,3,4,5,6,7,8,9 or 8 choices

therefore

Number of 3 digits number having 2 at unit place = 9 x 8 = 72

similarly

Number of 3 digits number having 2 at tens place = choices on ones place x choices on hundredth place = 9 x 8 = 72

Number of 3 digits number having 2 at hundredth place= choices on ones place x choices of hundredth place = 9 x 9 = 81

Therefore total 3 digit numbers have exactly one digit 2 in the number = 72+72+81 =225

Hence, there are 225  three digits number have exactly one digit 2 in the number

Answer 2

AMSWER :

SO THERE ARE 225 THREE DIGITS NUMBERS HAVE EXACTLY ONE DIGIT 2 IN THE NUMBER

=》225