Of the three-digit integers greater than 600, how many have two digits that are equal to each other and the remaining digit different from the other two?
Choose the correct choice from the following answers: A) 90 B) 82 C) 80 D) 107 E) 36
Three digit number can have only following 3 patterns:   A. all digits are distinct;   B. two digits are alike and third is different;   C. all three digits are alike.   We need to calculate B. B=Total - A - C   Total numbers from 600 to 999 = 399 (3-digit numbers greater than 600);   A. all digits are distinct = *4*9*8=288 (first digit can have only three values 7, 8, or 9   C. all three are alike =4 (666,777, 888, 999).   So, 399-288-4=107   Answer: 107
<result>D</result>
Of the three-digit integers greater than 600, how many have two digits that are equal to each other and the remaining digit different from the other two?