Can someone please explain this one in detail please?

Thank you!

The problem is attached.

The 'rephrased question' is what is 'x'. therefore statement 1 enables you to answer this as 350 miles. Statement 2 does not help to establish 'x'

So correct answer is A.

Can someone provide a DETAILED response please?

Thanks.

Time taken to travel x miles = (x/50) if we calculate X that would be sufficient to calculate the time.
As Shaji mentioned the rephrased question is what is x?

Information from the question - he drove x miles at 50 m/hr and the rest 60m/hr.

Statement (1)

Total distance - 530 miles
Total time = 10 hours assume he drove for t1 hrs at 50m/hr and t2 hrs at 60m/hr So

t1+t2 = 10

x/50 + (530-x)/60 = 10 ---from this euqation x can be calculated and so the time. SUFFICIENT

Statement (2)

Assume t1, t2 and t be the time time to travel x miles, the rest and the total time

So, t1 + t2 = t...(1)

t1 = t2 +4..(2) because Julio took 4 more hours to travel x miles than the rest.


Putting t1 from (2) in (1) t2 + t2+4 = t, we do not have the information about ehat the total time is, total distance travelled or average speed.

INSUFFICIENT. Hence the answer is (A)

Thanks, GMAT2007!