SOLUTION: Sam stuffs shrimp in his job as a seafood chef. He can stuff 1,150 shrimp in 7 hours. When his sister helps him, they can stuff 1,150 shrimp in 4.5 hours. If Sam gets sick, how lon

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: Sam stuffs shrimp in his job as a seafood chef. He can stuff 1,150 shrimp in 7 hours. When his sister helps him, they can stuff 1,150 shrimp in 4.5 hours. If Sam gets sick, how lon      Log On


   



Question 100223: Sam stuffs shrimp in his job as a seafood chef. He can stuff 1,150 shrimp in 7 hours. When his sister helps him, they can stuff 1,150 shrimp in 4.5 hours. If Sam gets sick, how long will it take his sister to stuff 575 shrimp?
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
sam can do 1/7 of the job in 1 hr.
sis +sam can do 1/4.5 of the job in 1 hr.
let 1/x=what part of the job sis can do in 1 hr
1/7+1/x=1/4.5
multiply 63 times both sides: 9x+63=14x
subtract 9x from both sides: 5x=63
x=63/5=12.6 hrs it takes her to stuff 1150 shrimp BUT she only has to stuff 1/2 that much (575) so the answer is 6.3 hrs.
Ed