Question 1174114
rt=q
r = rate
t = time
q = quantity


kevin stuffs 1500 shrimp in 4 hours.
his equation becomes r * 4 = 1500
solve for r to get:
r = 1500/4 = 375
that means he stuffs shrimp at a rate of 375 per hour.


when his sister helps him, they can stuff 1500 shrimp in 3 hours.
when they work together, their rates are additive.
let r = her rate.
their combined rate is r + 375
r is her rate, 375 is his rate.
formula becomes:
(r + 375) * 3 = 1500
solve for r + 375 to get:
r + 375 = 500
solve for r to get:
r = 500 - 375 = 125
her rate is 125 stuffed shrimp per hour.


confirm by replacing r with her rate to get:
(125 + 375) * 3 = 1500
combine like terms and simplify to get:
500 * 3 = 1500 becomes 1500 = 1500
this confirms the values are correct.


at 125 shrimps per hour, it would take his sister 750 / 125 = 6 hours to stuff 750 shrimp by herself.