Answer:
Can you take picture, please?
<span>251×263=66013, which is proof 66013 is not a prime.</span>
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
