A class has students: John, Sarah, Mike, and Lisa. The selection criteria are: John is not allowed to be selected with Mike. Sarah can only be selected if Lisa is also selected. Who can be selected together?
A store sells pencils for $0.50 each and erasers for $1.00 each. If a student buys a total of 10 items for $6.00, how many pencils did the student buy?
In a team of four: Tom, Jerry, Spike, and Tyke, the following rules apply: Tom cannot work with Jerry. Spike can work with either Tom or Jerry, but not both. Who can work together without violating the rules?