Kevin stuffs shrimp in his job as a seafood chef. He can stuff 1200 shrimp in 4 hours. When his sister helps him, they can stuff 1200 shrimp in 3 hours. If kevin gets sick, how long will it take his sister to stuff 600 shrimp?

Answer 1

consider 1200 shrimp One job.

1/3 = 1/4 + 1/t
t = 12
so, sis can stuff 1200 shrimp in 12 hours.
600 shrimp in 6 hours