Seema and Geeta start at the same time to ride from place A to place B, which is 90 km away from A. Seema travels 3 km per hour slower than Geeta. Geeta reaches place B and at once turns back, meeting Seema 15 km from place B. Geeta's speed (in km/h) is:
1
12
2
10.5
3
7.5
4
9