Find the distance (in miles) traveled by a car which moves at speed $s$ (in mi/h) for two hours, then moves $10$ mi $/$ h slower for another two hours.
A) $\frac { 14 } { 3 } s - \frac { 15 } { 2 }$
B) $4 s - 20$
C) $13 s - 15$
D) $\frac { 17 } { 2 } s - \frac { 227 } { 2 }$
E) $12 s - 1$

Question

Quizplus · Accepted Answer

The distance traveled in the first two hours is:

$$ d_1 = s \cdot 2 = 2s $$

The speed in the next two hours is $s - 10$, so the distance traveled in the next two hours is:

$$ d_2 = (s-10) \cdot 2 = 2s - 20 $$

The total distance traveled is the sum of these two distances:

$$ d = d_1 + d_2 = 2s + 2s - 20 = 4s - 20 $$

Therefore, the answer is choice B, $4s - 20$.

Find the Distance (In Miles) Traveled by a Car Which sss

Find the Distance (In Miles) Traveled by a Car Which $s$