Firstly they are both in different settings, get them both
to flight levels.
2000' QNH(1003) on 1013 would be 2300, so if your altimeter was always set to
1013(FL), then to fly to FL100 you would only have (10000-2300) left to fly.
7700/1000 = 7.7mins at 80kt GS
= 10.27 nm, 10.3 in the answer.