Two trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after 9 hours and 16 hours respectively. The ratio of their speeds is:
- (a) 2:3
- (b) 4:3
- (c) 6:7
- (d) 9:16
- (d) 9:16