Answer:
46 mph and 61 mph
Step-by-step explanation:
Distance=speed*time
Let speed of one bus be x and another x+15
After 3 hours
First bus would have traveled 3x while second bus 3(x+15)=3x+45
Total distance= 3x+3x+45=6x+45
6x+45=321
6x=321-45=276
x=276/6=46 mph
x+15=46+15=61 mph
110
4 x ( 3+ 52) ÷ 2
4 x 55 ÷ 2
220 ÷ 2 = 110
