On 2.26, it might help answering first this question: How much fence is she willing to buy? Then try representing the perimeter of the fence in terms of the width $w$ and use it to set up an inequality to find the possible values of the width that work.

For 2.27, let's say he drives $x$ hours at $60$ miles per hour; how many hours would he drive at $30$ miles per hour? How many miles would he drive at $60$ miles per hour? At $30$ miles per hour? In total? Then use this total number of miles (which should be an expression in $x$) to set up an inequality that would mean he beats his goal.

For 2.28, let's say Charlie's score is $c$; what is Danny's score? Franks score? Their total score? Then using the fact that the total score is at least $500$ set up an inequality to find all possible scores, $c$, that Charlie could have gotten.

Hope this hints help! Let us know if you need an extra push.