If all the numbers from 501 to 700 are written, what is the total number of times does the digit 6 appear?

To find how many times the digit 6 appears from 501 to 700, we analyze its occurrence in each place value. First, consider the range 501 to 600. In the units place, 6 appears 10 times: 506, 516, 526, up to 596. In the tens place, 6 appears 10 times: 560, 561, 562, up to 569. In the hundreds place, 6 appears 1 time: 600. So, from 501 to 600, there are 10 plus 10 plus 1, which equals 21 occurrences. Next, consider the range 601 to 700. In the units place, 6 appears 10 times: 606, 616, up to 696. In the tens place, 6 appears 10 times: 660, 661, up to 669. In the hundreds place, 6 appears 99 times: from 601 to 699. So, from 601 to 700, there are 10 plus 10 plus 99, which equals 119 occurrences. Adding both ranges together, 21 plus 119 equals 140. The correct answer is C.