Answer:
2a. If chagalti is being served, then you will have to use a tsibue.
2b. If you are using a tsibue, then chagalti is being served.
2c. If chagalti is not being served, then you dont have to use a tsibue.
2d. If you dont have to use a tsibue, then chagalti isnt being served.
2e. The converse must also be true because if you have to use a tsibue while eating chagalti, then when you arent eating chagalti, you dont need to use a tsibue.
Hope this helps!