Question

fan and medal help now .Frieda is keeping track of how many coupons she has saved on a piece of paper. She spilled some coffee on the paper.her list now looks like this blank represents where the coffe spill occured.started :30 coupons, 1 week: coupons 2 weeks: after 3 weeks :240 coupons. a. assume that the sequence of coupons is arithmetic.how many coupons did she have after one week,2 weeks? b.assume that the sequence of coupons is geometric.how many coupons did she have after 1 week, 2 weeks?

Answer 1

ok... so the pattern is

Week | start | 1 | 2 | 3 | 4
--------------------------------------
Coupons| 30 | ? | ? | 240 |

(a) if the sequence is arithmetic then the same value is added each week

this is called the common difference which can be found by d = (240 -30)/3

then d = 70

so in week 1 she has 30 + 70 =
Week 2 she has 30 + 70 + 70 =

see if you get the correct value for week 3


(b) for a geometric sequence you need

\[a_{n} = a \times r^{n -1}\]

you'll need to find r given

\[a_{4} = 240... a = 30,... and..... n = 4\]

the reason n = 4 is there there are 4 pieces of data

start, then weeks 1, 2, 3

so find r

\[240 = 30 \times r^{4 -1}\]

\[8 = r^3\]

so the common ratio is r = 2

so the pattern is

start = 30

week 1 = 30 x 2 =

week 2 = week 1 x 2 =

week 3 = week 2 x 2 =

see if it fits the pattern

Answer 2

I hope it all makes sense

Answer 3

thanks

Answer 4

can you help mew with another question

Answer 5

sorry I have to go and do some jobs

Answer 6

bye