Machines X and Y produced identical bottles at different constant rates. Machines X. operating alone of 4 hours, filled part of a production lot; then Machine Y, operating alone for 3 hours, filled the rest of this lot. How many hours would it have taken Machine X operating alone to fill the entire production lot?
1. Machine X produced 30 bottles per minute.
2. Machine X produced twice as many bottles in 4 hours as Machine Y produced in 3 hours.
Statement 1: X produced 30 bottles per minute.
Thus, the work produced by X in 240 minutes = r*t = 30*240.
No information about how much work was produced by Y.
INSUFFICIENT.
Statement 2: Machine X produced twice as many bottles in 4 hours as Machine Y produced in 3 hours.
Thus, for every bottle Y produced, X produced 2 bottles, implying that X produced 2 of every 3 bottles.
In other words, X produced 2/3 of the lot.
Since X took 4 hours to produce 2/3 of the lot, X would need 2 more hours to produce the remaining 1/3 of the lot, for a total of 6 hours.
SUFFICIENT.
The correct answer is
B.
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