How much thrust does the exhaust produce as a percentage of total thrust?

The correct choice reflects a common understanding of engine performance in jet propulsion. In many modern turbofan engines, the thrust produced by direct exhaust gases contributes significantly to the overall thrust generated by the aircraft, but this contribution can vary depending on the engine design and the bypass ratio.

For many engines, especially those with a high bypass ratio, the majority of thrust is produced by the bypass air rather than the exhaust gases. The percentage of thrust from exhaust gases often falls within a range that can include percentages like the one given in the correct answer.

In this particular context, the value of 6% indicates that the exhaust gases indeed produce a smaller proportion of the total thrust compared to the bypass air, reflecting a typical characteristic of high-bypass turbofan engines that are efficient and designed for optimal performance, especially in commercial aviation operations.