You divide the numerator by the denominator
This kind of problems requires to add the working velocities. The total velocity is the sum of the individual velocities.
Anita's velocity = 1 pool/8 hours
Chao's velocity = 1 pool/6 hours
Combined velocity 1/8 + 1/6 = (3 + 4)/24 = 7/24 pool/hour
Time = 1 pool / (7/24) pool/hour = 24/7 hour =3.43 hours
Answer: 0.92
1-4: stay the same
5-9: round up!
