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| Suppose that you are a traffic-light timing expert for a medium
sized city with an increasing population. More people means more drivers, which
means more traffic control devices. Use what you learned about fractions, percents,
ratios, proportions, probabilities, and decimals to solve these problems involving the
timing of traffic lights. |
| A light on Washington Street is currently set at 3 minutes for green, 1
minute for yellow, and 2 minutes for red for each cycle. Write the fractions for the
amount of time that thelight spends on each color during one cycle. Be sure to write
them in simplest form. |
1. |
green ______ |
2. |
yellow ______ |
3. |
red _______ |
|
|
 |
The light at the same intersection on Lincoln
Street is green for 1 1/2 minutes, yellow for 1/2 minute, and red for 4 minutes.
Write the fractions for the amount of time in minutes that the light spends on each color
for one cycle. Be sure to write them in simplest form.
4. |
green ______ |
5. |
yellow ______ |
6. |
red _______ |
|
| On Sunday through Thursday the traffic lights at this intersection operate
from 5:00 am until 10:00 pm. The remainder of the time, the lights flash yellow in
one direction and red in the other direction. Based on the timing ratios you
calculated above, calculate the number of minutes that the lights are on each color on a
Monday. Remember to consider only the amount of time the lights are operating
normally, not flashing. |
7. |
Washington Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
8. |
Lincoln Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
|
| On Friday and Saturday, the same traffic lights operate on
the same cycle from 5:00am until midnight. Calculate the number of minutes that the
lights are each color on a Friday. |
9. |
Washington Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
10. |
Lincoln Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
|
| Calculate the amount of time in hours that the lights spend
on each color for one week: Sunday at 5:00 am to Saturday at midnight. Give your
answer in hours and fractions of hours, not in hours and minutes. |
11. |
Washington Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
12. |
Lincoln Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
|
| Write the ratios for the colors of the traffic light in terms
of
number of hours on each color in
one week
number of hours operating normally(not flashing) in a week |
13. |
Washington Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
14. |
Lincoln Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
|
| Convert these ratios to percents. |
15. |
Washington Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
16. |
Lincoln Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
|
The intersection is becoming busier, and the traffic light
timing needs to be altered. If the times for one cycle are altered as listed below,
write the fractions for the amount of time in seconds that the light spends on each color
for one cycle. Be sure to write in simplest form.
|
Washington Street: |
|
| green = 5 min. |
yellow = 1.5 min. |
red = 3 min. |
|
|
Lincoln Street: |
|
| green = 2 min. |
yellow = 1 min. |
red = 6.5 min. |
|
|
17. |
Washington Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
18. |
Lincoln Street: |
|
| green _____ |
yellow _____ |
red _____ |
|
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