If x% of four-digit numbers have a repeated digit of 3, then what is x ? Express your answer as a decimal to the nearest tenth.
There are: 9,999 - 1,000 + 1 =9,000 four-digit numbers between 1,000 and 9,999.
There are: 495 numbers with AT LEAST two 3 in them. Therefore:
The probability is: 495 / 9,000 =5.5% have a repeated digit of 3 in them.
