Question

The ideal length of a certain nail is 20mm. The actual length can vary from the ideal by at most 0.4 mm. What is the range of acceptable lengths of the nail?

a) 20.4 mm to 19.6 mm
b) 21.0 mm to 20.0 mm
c) 20.8 mm to 19.2 mm
d) 20.5 mm to 19.5 mm

Answer 1

The range of acceptable lengths for a nail with an ideal length of 20mm, which can vary by at most 0.4 mm, is from 19.6 mm to 20.4 mm. So the correct answer is option A.

Step-by-step explanation:

The ideal length of a certain nail is 20mm, and the actual length can vary by at most 0.4 mm. This means that the nail can be either 0.4 mm shorter than the ideal length or 0.4 mm longer. To find the range of acceptable lengths, we subtract 0.4 mm from the ideal length and also add 0.4 mm to the ideal length:

• For the shortest acceptable length: 20 mm - 0.4 mm = 19.6 mm
• For the longest acceptable length: 20 mm + 0.4 mm = 20.4 mm

Therefore, the range of acceptable lengths for the nail is 19.6 mm to 20.4 mm.

The correct answer is: (a) 20.4 mm to 19.6 mm.