A bungee jumper falls 97.2 feet before bouncing back up at the end of his bungee cord. Then he falls 64.8 feet before bouncing up again. On his third descent, he falls 43.2 feet before going back up. What is the total distance the bungee jumper drops after five falls if the distances continue in this pattern? (Do not include the distance traveled up.)
A)234.0 ft
B)253.2 ft
C)789.8 ft
D)1,281.8 ft

Question

A bungee jumper falls 97.2 feet before bouncing back up at the end of his bungee cord. Then he falls 64.8 feet before bouncing up again. On his third descent, he falls 43.2 feet before going back up. What is the total distance the bungee jumper drops after five falls if the distances continue in this pattern? (Do not include the distance traveled up.)
A)234.0 ft
B)253.2 ft
C)789.8 ft
D)1,281.8 ft

amistre64 · Answer

hmm, what models the pattern best?  what type of sequence?

dedi · Answer

Geometric sequence

amistre64 · Answer

lets chk that

if its geometric, then we have a common ratio

97.2/64.8 = 64.8/43.2

which is good, so we know our r value

amistre64 · Answer

given a starting value a1,  and a common ratio , r

we can use the formula:$$S_n=a_1\frac{1-r^n}{1-r}$$

dedi · Answer

okay is it d?

amistre64 · Answer

not when we use the formula, i dont get d

amistre64 · Answer

define the varaibles for me:  a1, r and n

dedi · Answer

I think its 97.2,64.8

amistre64 · Answer

a1 is 97.2

and since a1 r = a2;  r = a2/a1

and n is stated for 5

dedi · Answer

is it b or c?

amistre64 · Answer

lets use the formula ....

amistre64 · Answer

what is that value of r, since we have already defined a1 and n