both the second and fourth ones look right to me, but i'm pretty sure its the fourth option.
Plug n = 1 into the expression 20-9n and we get
20-9n = 20-9*1 = 20-9 = 11
So 11 is the first term of the series that we add up. Therefore the answer must be choice C, which has 11 listed as the first term added
A mile or two can add up to ether 5,280 or 1,760 I'm sorry I'm kinda good at math hope that helps
The easiest way to find percent is to make the percent into a decimal and multiply. Move the decimal to places to the left to make 4.30, and multiplied by 90 equals 387, so 430 percent of 90 is 387.