Statement 1
Of all the cars manufactured in factory Q, 60% were still in operation at the end of last year.
This indicates that all the cars that has even been manufactured by factory Q not just the cars manufactured last year, we cannot find the exact estimate of the numbers that were still in operation out of last year's manufactured cars because 60% given is referring to all cars starting from when factory Q started manufacturing cars, Hence statement 1 is NOT SUFFICIENT.

Statement 2
A total of 48,000 cars manufactured in factory Q was still in operation at the end of last year.
This tells us the total car ever manufactured in factory Q were still in operation last year, but there is no way to find the number manufactured
last year that were still in operation, Hence statement 2 is INSUFFICIENT.

Combining statement 1 and 2 together
We know the numbers of cars manufactured in factory Q last year and the numbers of all cars ever manufactured by factory Q that were in operation last year. However, using this if it is not possible to determine the number of cars manufactured in factory Q last year that were still in operation by the end of last year.

The two statements combined together are NOT SUFFICIENT.
final answer = option E