While flying across the country, did Karen ever exceed 650 miles per

(1) Karen flew 3,000 miles.
We only have information about distance flown by Karen . We have no information of average and max speed .
Not sufficient

(2) Karen flew for 5 hours
We only have information about total time of flight .
Not sufficient

Combining 1 and 2 , we get
Average speed = 3000/5 = 600 miles / hour
We have no information about max speed .
Not sufficient
There are 2 possibilities -
Karen flew at a constant speed of 600 miles per hour throughout the journey .
or She her speed varied across the journey - in this case there might be possibility that her max speed was more than 650 miles per hour

Answer E
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NOTE: There's nothing here to suggest that Karen's speed was constant. Sure, she MIGHT have traveled at a constant speed, or her speed may have varied throughout the trip.

Target question: Did Karen's speed ever exceed 650 miles per hour?

Statement 1: Karen flew 3,000 miles
No information about Karen's travel TIME so statement 1 is NOT SUFFICIENT
Consider these two possible scenarios that yield conflicting answers to the target question:
Case a: flying at a constant speed, Karen spent 1 hour flying 3000 miles, in which case her speed was 3000 miles per hour. So, Karen's speed DID exceed 650 miles per hour
Case b: flying at a constant speed, Karen spent 10 hours flying 3000 miles, in which case her speed was 300 miles per hour. So, Karen's speed did NOT exceed 650 miles per hour
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: Karen flew for 5 hours
No information about the DISTANCE Karen traveled. So, statement 2 is NOT SUFFICIENT
Consider these two possible scenarios that yield conflicting answers to the target question:
Case a: flying at a constant speed, Karen spent 5 hours flying 5000 miles, in which case her speed was 1000 miles per hour. So, Karen's speed DID exceed 650 miles per hour
Case b: flying at a constant speed, Karen spent 5 hours flying 5 miles, in which case her speed was 1 mile per hour. So, Karen's speed did NOT exceed 650 miles per hour
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Consider these two possible scenarios that yield conflicting answers to the target question:
Case a: flying at a constant speed, Karen spent 5 hours flying 3000 miles, in which case her speed was 600 miles per hour. So, Karen's speed did NOT exceed 650 miles per hour
Case b: Karen flew 2000 miles (at a constant speed) for 1 hour, and then spent 4 hours flying the remaining 1000 miles. So, Karen's speed DID exceed 650 miles per hour
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer:

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Since the question is whether Karen ever exceeded 650 miles/hour,
we need to check, if her speed was ever over 650 miles/hour?

(1) Karen flew 3,000 miles.
Knowing the distance traveled will never be enough to determine if the speed was over or below 650.
Hence, this statement alone is insufficient.

(2) Karen flew for 5 hours.
Knowing the time alone, Karen takes to travel the distance, is never going to be enough to calculate the speed.
This statement alone is insufficient.

Combining both statements, we know she travels 3000 miles in 5 hours.
If she travels at a constant speed, we can clearly tell the speed never exceeded 650 miles/hour
However, if she doesn't travel at a constant speed(and since this information is never explicitly given in the question stem,
or either statements) we cant clearly tell if her speed exceeded 650 miles/hour for an hour or not.
Hence, combination statements are also insufficient (Option E)

by reviewing both the statements we could say that it is not clear whether he traveled 650m/h or not . hence E , as speed is not constant here

We need to determine whether Karen’s rate ever exceeded 650 mph.

Statement One Alone:

Karen flew 3,000 miles.

Since we do not know anything regarding her time, we cannot determine whether her rate was greater than 650 mph. Statement one alone is not sufficient to answer the question.

Statement Two Alone:

Karen flew for 5 hours.

Since we do not know anything regarding her distance, we cannot determine whether her rate was greater than 650 mph. Statement two alone is not sufficient to answer the question.

Statements One and Two Together:

Using statements one and two, we know that Karen flew 3,000 miles for 5 hours. While it may appear as though her rate was 3,000/5 = 600 mph, we do not know whether she flew at a constant rate. Thus, she could have flown the entire trip at 600 mph or she could have flown at a rate that was sometimes less than 600 mph and sometimes greater than 650 mph.

Answer: E
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I guess the plane must have took off directly at the speed of 600mph

Correct Answer - E.

Distance = Rate x Time

I. This statement provides us the distance, but not the time. Not Sufficient.
II. This statement provides us the time, but not the distance. Not Sufficient.

Together - We have both the distance and the time. Therefore, we can determine that Karen's average speed was 600 mph, which is less than 650 mph. However, this number represents Karen's average rate of travel. It is possible that Karen traveled over 650 mph for a portion of the trip and less than 600 mph for a portion of the trip, but on the average traveled 600 mph. Not sufficient.

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