http://gyazo.com/b031e9d54f9512e5a583a4ed0ea28a0a the answer is 2/3: my attempt: one side X~U[1,7] the longer part of this side, call Y, where Y~[4,7] P(Y>6) = 1/3 don't see how they got 2/3, they have 3 different methods in the answers, but none doing my method. I'm thinking, as there are two sides in the rectangle and I've only limited mine to one side then if I multiply that by 2 I'll get the answer - or is that even relevant? I'll give another example where I used my method and it works: http://gyazo.com/a582f228a9dd22370303f25b69d5bf6c part c) the shorter side can be distributed by X~U[0,10] P(X>8) = 1/5 which is the answer, but this doesn't work for the original method. Any ideas why? Thanks.