Question

The wool of a vicuna is finer than any other wool. The hair of this animal can be as thin as 0.000006 meters. If the average thickness of human hair is approximately 8.4 × 10-5 meters, what is the difference of the thickness of a human hair and a vicuna hair?
A.2.4 × 10-5 meters



B.2.4 × 10-6 meters



C.7.8 × 10-6 meters



D.7.8 × 10-5 meters

Answer 1

Answer: $7.8 \times 10^{-5} \text{ meters}$

Step-by-step explanation:

The length of a vicuna hair = 0.000006 = $0.6 \times 10^{-5}$

And, the length of the a human hair = $8.4\times 10^{-5}$

Thus, the difference between the human hair and vicuna hair

$= 8.4\times 10^{-5}-0.6\times 10^{-5}$

$=10^{-5}(8.4-0.6)$

$=10^{-5}(7.8)$

$=7.8\times 10^{-5}$

⇒ Option D is correct.