Bang Guy - technically, you are correct, but since this is a multiple guess test and "1" is not a choice, I'm deducing they are looking for the number of times "7" is one of the digits composing a number in the count.
Holy Guacamole! I think I just confused myself
20 is the correct answer. Thanks for playing. Oh by the way I ot it wrong the first time also.
7, 17, 27, 37, 47, 57, 67, 70, 71, 72, 73, 74, 75, 76, 77 is 2, 78, 79, 87, 97.