BTGmoderatorDC wrote:At what speed was Erik running when he was at the halfway point of his route?

1. Erik's route was 10 miles long and took him 2 hours to complete.
2. Erik ran at an average speed of 5 miles per hour on the route

OA E

Source: Veritas Prep

We are asked to find out Erik's speed when he was at the halfway point of his route. Note that his speed may vary through his route many times.

Let's take each statement one by one.

1. Erik's route was 10 miles long and took him 2 hours to complete.

From this data, we can compute Erik's average speed = 10 miles / 2 hours = 5 miles per hour. But Erik's could have been running at the halfway at 5 mph, greater than 5 mph or less than 5 mph. No unique answer.

2. Erik ran at an average speed of 5 miles per hour on the route.

This is the same statement as Statement 1. Insufficient.

(1) and (2) together

Both the statements are actually the same. Insufficient.

The correct answer: E

Hope this helps!

-Jay
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BTGmoderatorDC wrote:At what speed was Erik running when he was at the halfway point of his route?

1. Erik's route was 10 miles long and took him 2 hours to complete.
2. Erik ran at an average speed of 5 miles per hour on the route

OA E

Source: Veritas Prep

IMPORTANT: The two statements essentially provide the exact same information.
If it took Erik 2 hours to travel 10 miles, we can conclude that his average speed was 5 miles per hour.
When the two statements provide the same information in a Data Sufficiency question, the correct answer must be either D or E

Target question: At what speed was Erik running when he was at the halfway point of his route?

Statements 1 and 2 combined
There are several scenarios that satisfy BOTH statements. Here are two:
Case a: Erik traveled the first 1 mile at 1 mile per hour, and then traveled the last 9 miles at 9 miles per hour. So, at the halfway mark (upon completion of the 5th mile), Erik was running at a speed of 9 mph
Case b: Erik traveled the first 2 miles at 2 miles per hour, and then traveled the last 8 miles at 8 miles per hour. So, at the halfway mark (upon completion of the 5th mile), Erik was running at a speed of 8 mph
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer: E

Cheers,
Brent