you have flown from NZPN on track NZWN you arrive at NZPP and are instructed to hold. How much time can you hold NZPP arriving at NZWN with legal reserve plus 15 mins. there are about 6 calculations in that question.... how much fuel have i already used
Unfortunately it's questions like this that make the multiple choice questions more difficult. In the days of "show your workings" you might of got some marks for steps 1-5 even if it was step 6 that meant you got the question wrong.
On the other hand, in the real world it doesn't matter why you were wrong, if you miscalculate your fuel you're going down.