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
Perimeter: x + (4x + 9) + (x + 11)
The value x is for the bottom of the triangle.
Simplified, it would be 6x + 20
Total number of ways to make a pair:
The first player can be any one of 7 . For each of those . . .
The opponent can be any one of the remaining 6 .
Total ways to make a pair = 7 x 6 = 42 ways .
BUT ... every pair can be made in two ways ... A vs B or B vs A .
So 42 'ways' make only (42/2) = 21 different pairs.
If every pair plays 2 matches, then (21 x 2) = <em><u>42 total matches</u></em> will be played.
Now, is that an elegant solution or what !