Question

how many three digits numbera are there in all​

Answer 1

In the tens place and the ones place, there can be any digit from 0-9. There are possibility of 10 digits in hundredth place and 10 digits in units place. Thus, there are 9 × 10 × 10 = 900 three digit numbers in all. Therefore there are 900 three-digit numbers in all.

Answer 2

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In the tens place and the ones place, there can be any digit from 0-9. There are possibility of 10 digits in hundredth place and 10 digits in units place. Thus, there are 9 × 10 × 10 = 900 three digit numbers in all. Therefore there are 900 three-digit numbers in all.