Nearly a tie: Libya and Mongolia differ by barely -4%% in area — about 1,626,369 km² km² against 1,560,428 km² km².
Libya sits in Africa, Mongolia in Asia. On the old Mercator map the latitude gap distorted how large each felt beside the other; at true size the answer is simply 1×.
The old map muddied it further: Mercator inflates Libya about 1.3× and Mongolia about 2.2×, so on a Mercator-style map this pair appears 1.6× apart instead of the true 1×.
Libya fits 0× into Mongolia.