Question

The ideal length of a particular metal rod is 20.5 cm. The measured length may vary from the ideal length by at most 0.045 cm. What is the range?
*the equal sign is for less than / greater than or equal to*

A) X<= 20.455 or X>=20.545
B) 20.455 >= x <= 20.545
C) 20.454 >= x >= 20.545
D) 20.455 <= X <= 20.545

Answer 1

To answer this item, we are first to calculate the values of the length of this particular metal rod that is 0.045 cm less than the given,
             Lower limit = 20.5 cm - 0.045 cm = 20.455 cm

Also, we calculate for the upper limit by adding 0.045 cm to the given length. 
            Upper limit = 20.5 cm + 0.045 cm = 20.545 cm

Thus, the answer to this item is D. 

Answer 2

Answer:

Option: D is the correct answer.

D) 20.455 <= X <= 20.545

Step-by-step explanation:

We are given The ideal length of a particular metal rod is 20.5 cm.

It is given that:

The measured length may vary from the ideal length by at most 0.045 cm.

By atmost we mean either less than or equal to that amount but not more than that.

It means that:

|X-20.5|≤ 0.045

⇒  -0.045  ≤ X-20.5 ≤ 0.045

⇒    -0.045+20.5 ≤ X ≤ 20+0.045

⇒   20.455 ≤ X ≤ 20.545.

Hence, option D is true.

D) 20.455 <= X <= 20.545