Find the sum of the range and the mode of the set of numbers 10, 9, 10, 9, 8, 7, 7, 10, 8, 10, 8, 4, 6, 9, 10, 9, 7, 10, 6, 5

The range is the difference between the highest and lowest values in a set. To find the range of the given set of numbers, we need to first find the highest and lowest values. The lowest value in the set is 4, while the highest value is 10. Therefore, the range is 10 - 4 = 6. The mode is the value that appears most frequently in a set. To find the mode of the given set of numbers, we need to count how many times each value appears and find the value that appears most frequently. The value 10 appears 5 times in the set, which is more than any other value. Therefore, the mode of the set is 10. To find the sum of the range and the mode, we simply add the two values together. In this case, the range is 6 and the mode is 10, so the sum is 6 + 10 = 16. Therefore, the correct answer is: 16.