Cameron answered 2 * 6 = <<2*6=12>>12 questions for the first group.
He answered 2 * 11 = <<2*11=22>>22 questions for the second group.
The third group had 8 - 1 = 7 tourists that asked 2 questions each.
The third group also had 1 tourist that asked 2 * 3 = <<1*2*3=6>>6 questions.
Thus, the third group asked 7 * 2 + 6 = 14 + 6 = <<7*2+6=20>>20 questions.
The last group asked 7 * 2 = <<7*2=14>>14 questions.
For all four tours, Cameron answered 12 + 22 + 20 + 14 = <<12+22+20+14=68>>68 questions.
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