Question

Whitney left school and drove 7 miles to meet her mother at a restaurant. Her mother left at the same time and drove 8 miles, traveling 5 miles faster then her daughter. If the two arrived at the restaurant at the same time, what was whitney's speed

Answer 1

Let's write the cinematic equation for Whitney and her mother.
We have then:
For Whitney:
d = v * t
7 = v * t
For her mother:
d = (v + 5) * t
8 = (v + 5) * t
Where,
v: speed
t: time
We have then how the time is the same:
7 / v = 8 / (v + 5)
We cleared v:
7 (v + 5) = 8v
7v + 35 = 8v
8v-7v = 35
v = 35 mph
Answer:
whitney's speed is:
v = 35 mph