Answer: Choice B) The plane is at least 20 times faster than the bird
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Step-by-step explanation:
We'll divide the speed of the plane over the speed of the bird.
First divide each coefficient of the scientific value expressions:
7/3 = 2.33 approximately
Then divide the 10^n exponent expressions and we get
10^3 divide by 10^2 = 10^(3-2) = 10^1
So overall, the result of dividing the two speeds leads to approximately
2.33*10^1 = 2.33*10 = 23.3
This shows the plane is approximately 23.3 times faster compared to the bird. Saying "The plane is at least 20 times faster than the bird" is fairly close to the prior sentence, so the statement is valid. That's why choice B is the answer.
Choices A and C are saying similarly valid statements, just written in different formats. I think choice B is the best answer since it seems to be the most direct comparison that is fairly easy to grasp.