Do not be intimidated by the question. The percentages are merely fractions expressed in a different form. Do it as you would for other questions dealing with percentages. My solution here appears long, but the method is actually quite short, if not for all the workings. I hope the explanation is able to help. I believe you got confused at the 30% increase for child tickets. And you did a good job identifying it was a trick question. You MUST note that 30% increased tickets for children does not mean it was 70% at first. 7/10 is NOT the same as 10/13.