Well I look at it this way: If Pat was 10, that would mean that Ron is 25. Add those together & they equal 35, so we know that can't be the answer, since the sum of their ages is less than 35, not equal to it & under. So the next highest number would be 8. To test that this is correct, we'd do 8 plus 16 (8*2) plus 5 which would come to 29. Hope I helped!
