D. because there is one measurement or rate over one unit. In this case, 1 gallon. The one at the denominator is important in figuring out which one is a unit rate.
Hope this helps.
A, is your answer ! Hope it helps
The partial sum of a geometric sequence is

In your case a=3, so if we sum N terms of the sequence we have

We want this to me more than 1 million, so we have

Considering the log (base 3) of both sides, we have

So, starting from N=13, the sum of the first N terms will be more than 1 million
Well 1 metre= 100cm and 1cm=10mm
So there are 600cm in 6 metres and to find the amount of mm you would have to times 600 by 10 which is 6000mm.
1. the number five plus x
2. the number five minus x
3. five times x
4. five divided by x
5. three-forths of x plus two
6. two minus three-forths of x
7. three times x plus ten
8. ten times x plus three