Bunuel
If the capacity of tank X is less than the capacity of tank Y and both tanks begin to fill at the same time, which tank will be filled first?
(1) Tank X is filled at a constant rate of 1.5 liters per minute.
(2) Tank Y is filled at a constant rate of 120 liters per hour.
DS21243
Given: The capacity of tank X is less than the capacity of tank Y and both tanks begin to fill at the same time Target question: Which tank will be filled first? Statement 1: Tank X is filled at a constant rate of 1.5 liters per minute. Since we have no information about the rate at which tank Y is filled, statement 1 is NOT SUFFICIENT
Statement 2: Tank Y is filled at a constant rate of 120 liters per hour.Since we have no information about the rate at which tank X is filled, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined Statement 1 tells us that tank X is filled at a constant rate of
1.5 liters per minute.
Statement 2 tells us that tank Y is filled at a constant rate of 120 liters per hour
In other words, tank Y is filled at a constant rate of 120 liters per 60 MINUTES
In other words, tank Y is filled at a constant rate of
2 liters per MINUTE
We can see that
tank Y is filled at a faster rate that tank X is filled.
However, since
tank Y has a greater volume that tank X, it's impossible to determine which tank gets filled first.
To better understand what I mean, consider these two possible cases:
Case a: Tank X holds
15 liters and tank Y holds
16 liters.
Time to fill a tank = (tank's volume)/(rate) So, time to fill tank X =
15/
1.5 = 10 hours
Time to fill tank Y =
16/
2 = 8 hours
In this case, the answer to the target question is
tank Y is filled firstCase b: Tank X holds
1.5 liters and tank Y holds
16 liters.
Time to fill a tank = (tank's volume)/(rate) So, time to fill tank X =
1.5/
1.5 = 1 hour
Time to fill tank Y =
16/
2 = 8 hours
In this case, the answer to the target question is
tank X is filled firstSince we cannot answer the
target question with certainty, the combined statements are NOT SUFFICIENT
Answer: E
Cheers,
Brent