Direct flight from bathurst to dubbo. you depart YBTH and 2305 UTC and at 2317 UTC you obtain a pinpoint over HILL END township 25nm from YBTH.

using this data to estimate for YSDU is closest to -

A) 2355 UTC
B ) 2400 UTC
C) 2342 UTC
D) 2348 UTC

My working out was: 2317 - 2305 = 12minutes. the plane is doing 25NM in 12 minutes
another 65NM to dubbo at 125GS is 31 minutes.

2317 + 31 = 2343 closest is 2342 UTC but in my KDR the answer is wrong.

Oops.. Just check the math, you've done everything else correct! I would pick answer (d)

i was contemplating between 2342 and 2348, due to that you never round down. but then what tricked me is the question says closest. clearly 2343 is closer to 2342 rather than 2348.

I reckon what Ellzy was referring to was a simple maths mistake in your final step: 2317 + 31 is 2348, not 2343. 2348 is bang on option D.

That would be grounds for a facepalm in the exam