Question

What is wrong with this road sign:

Memphis 7 mi (11.263 km)?

Short answer

The road sign Memphis 7 mi (11.263 km) is the incorrect way of expressing distance.

Step-by-step solution

Defining significant figures

In a number, significant figures are the digits that indicate the quantity of a thing. These are crucial in mathematical calculations.

Counting the significant digits

In the road sign Memphis 7 mi, there is one significant digit. However, in 11.263 km, there are five significant digits. The value in kilometers is more accurate and precise than that in miles.

Correct way of giving road signs 

Road signs convey important information to the drivers.These signs help in ensuring road safety. Pictures are preferred over words for making road signs as they are easier for people to understand and recognize. Road signs are divided into four groups:

1. Regulatory: They inform about the prohibition of entry, left or right turn, etc.

2. Warning: They give a warning regarding the changes in the road ahead.

3. Guidance: They give information about the route followed.

4. Temporary: They convey entry restrictions to a place due to an accident or construction work.

Sketch showing road signs