PLEASE HELP WILL FAN AND MEDAL.

Question

love_to_love_you · Answer

D'Andre has decided that he needs to get more exercise, so he is building a running regimen for himself. He decides that, beginning on Sunday, he'll run 10 feet. On each subsequent day, he'll double the distance he ran the previous day. So he'll run 20 feet on Monday, 40 feet on Tuesday, and so on. His Track coach (who also happens to be his math teacher) told D'Andre that he won't be able to keep to his plan for very long, but D'Andre is determined to make it work for at least two weeks.

a. According to his plan, how far will D'Andre have to run on the 14th day? Give your answer to the nearest tenth of a mile (1 mile=5,280 feet).

b. If D'Andre sticks to his plan, how far will he have to run in those 2 weeks? Give your nearest answer to the nearest tenth of a mile.

Show all work.

love_to_love_you · Answer

@shrutipande9

love_to_love_you · Answer

@surjithayer

anonymous · Answer

it is a geometric series problem
with first term a=10 feet
common ratio r=2
n=14
find $$a _{14}$$
$$a _{n}=a*r ^{n-1}$$

anonymous · Answer

to convert in miles 
divide the result you got by 5280

anonymous · Answer

$$S _{n}=a \frac{ r^n-1 }{ r-1 }$$
here a=first term=10 feet
r=common ratio=2
n=14

find $$S _{14}$$