High School

If a little old lady is driving at 98.3 kilometers per hour, will she get a speeding ticket if the speed limit is 55 miles per hour?

Use the following conversions:
- 1 mile = 5280 feet
- 1 inch = 2.54 cm

Show how to convert her speed to miles per hour, even if your calculator does it for you.

Answer :

The little old lady's speed (61.11 mph) is greater than the speed limit (55 mph), she will get a speeding ticket.

1. Convert the little old lady's speed from kilometers per hour to miles per hour:

[tex]\[ 98.3 \, \text{km/h} \times \frac{1 \, \text{mile}}{1.60934 \, \text{km}} \approx 61.11 \, \text{mph} \][/tex]

2. Compare her speed to the speed limit:

[tex]\[ \text{Little old lady's speed} = 61.11 \, \text{mph} \][/tex]

[tex]\[ \text{Speed limit} = 55 \, \text{mph} \][/tex]

Since the little old lady's speed (61.11 mph) is greater than the speed limit (55 mph), she will get a speeding ticket.

Answer:

It is possible she could get one.

Explanation:

To solve this problem we need to convert 98.3 kilometers/hour to miles/hour.

In other words, we convert km to mi, to do so we multiply 98.3 km by a conversion factor, putting the unit we want to have in the numerator, and the unit we want to convert in the denominator:

  • 98.3 km * [tex]\frac{1000m}{1km} *\frac{100cm}{1m}*\frac{1in}{2.54cm} *\frac{1ft}{12in} *\frac{1mi}{5280ft}[/tex] = 61 mi

Given that the little old lady is doing 61 miles/hour, she could get a speeding ticket.