Marina, Mike, Roger, Phillip and Justin has each only one hobby from the following list: motocross, badminton, swimming, athletics and karate, but not necessarily in that order. It is known that:
- Who does swimming and Marina don't know each other.
- Justin needs a vehicle for his hobby.
- The one who does karate and Roger are friends since childhood.
- Mike is a relative of the one who does athletics who in turn is friends with Phillip.
- The one who does badminton is a friend of Phillip and of the one who does martial arts.
Who is the person that does athletics and what is Mike's hobby?.
The alternatives given in my book are as follows:
- Roger and badminton
- Mike and athletics
- Phillip and badminton
- Marina and karate
I want to use a logic grid to approach this. I attempted building one and I have this:
Which leads me to decide between these two apparently valid choices:
There are three people for whom I can't decide what their hobby is, as the three choices left are valid for each group. The first answer appears in the alternatives as "Roger and badminton". The second answer appears also in the alternatives as "Marina and karate".
How can I decide between them?