1. The problem statement, all variables and given/known data I've spent a few hours but unable to work out the solution of the following questions successfully. The question is as follows: I am having problems with (a)(iii) and (b)(ii) 2. Relevant equations 3. The attempt at a solution (a)(iii) Although I can work out the solution at last, my original attempt was incorrect but I don't understand why. My first attempt: P(pass) = P(4 answer correct) + P(5 answer correct) + P(all answer correct) = (3x3x1x1x1x1)/(6x6x6x6x6x6) + (3x1x1x1x1x1)/(6x6x6x6x6x6) + (1x1x1x1x1x1)/(6x6x6x6x6x6) However, this is wrong. But I don't understand why............ (b)(iii) I can't work out the solution at all. Please help. Thank you.