Time of Party A: 1 hour 30 minutes+15 minutes = 1.75 hours.

Time of Party B: 1 hour 30 minutes = 1.5 hours.

1.5*3x- 1.75*2x=6

x=6

Speed of a: 2x= 12

Speed of B: 3x= 18

Distance between two places:12 *1.75+18 *1.5 = 21+27 = 48.