Question

Ramp meters are often used in and around metropolitan areas to reduce freeway congestion during AM and PM rush hours. Depending on freeway volume, ramp meters in London allow one car onto the freeway every $5-9$ seconds. Assuming a constant ramp car queue, between the hours of $3:30$ PM and $6:30$ PM, how many more cars move through a ramp meter with a $5$-second interval than one with an $8$-second interval?

• A. $270$
• B. $320$
• C. $810$
• D. $960$

Answer 1

The correct option is C $810$

$3$ $hour=180min=180\times 60sec=10800sec$

Now, Cars passing Through ramp-meter of 5-second interval

$=\frac{10800}{5}=2160$

and Cars passing Through ramp-meter of 8-second interval

$=\frac{10800}{8}=1350$

Now,

$\Rightarrow 2160-1350=810$

Therefore Answer is $\left(C\right)$