1 tsp (US) = 4.93 mls

There are various ways/approaches that one can take to answer this question. The following is just one.

4 days x 24 hrs / day = 96 hours

1 dose q 6 hrs for 96 hrs = **16 doses total**

3 btls x 60 mls = 180 mls

180 mls x 1 tsp / 4.93 mls = **36.5 tsps total**

36.5 tsps / 16 doses = 2.3 tsps per dose

Answer would be 2 tsps should be taken for each dose.