Answer: Destiny's speed is 11 mph.
Alicia's speed is 15 mph
Step-by-step explanation:
Destiny and Alicia both leave the coffee shop at the same time, but in opposite directions. If they are 78 miles apart after 3 hours, it means that the total distance that they covered in 3hours is 78 miles
Let x represent the speed at which Destiny travelled. If Alicia travels 4 mph faster than Destiny, it means that the speed at which Alicia travelled is (x + 4) mph
Distance = speed × time
Distance covered by Destiny in 3 hours is
3 × x = 3x
Distance covered by Alicia in 3 hours is
3(x + 4) = 3x + 12
Since the total distance is 78 miles, then
3x + 3x + 12 = 78
6x = 78 - 12 = 66
x = 66/6 = 11 mph
Alicia's speed is
11 + 4 = 15 mph
