Question

Is someone kind and available enough to do this work for me
I need it really

Answer 1

D. 40.0km

Explanation:

When rounding to 3 significant figures, we will have to look at the 4th significant figure. If that figure is 1-4, you round the 3rd figure down. If that figure is 5-9, you round the 3rd figure up.

In this case, the 3rd figure is the tenth 9 and the 4th figure is the hundredth 7.

Since 7 is from 5-9, you round the tenth 9 up. This adds one whole to 39, which makes it 40. You also need to keep 3 significant figures so the decimal zeros are significant. Thus, the answer is 40.0km