series question (1 Viewer)

[talulahbay]

A lamb grows by 2/5 of its previous growth each month. If a lamb is 45cm tall,
a) how tall will it be after 6 months?

i keep getting like 388 for part a but when you do the limiting sum to see its final height i get 75 can any help pleaseee

 

[anthony_wheels]

You stated that is grows by 2/5 of its previous growth each month, however, what is its initial growth?

 

[Menomaths]

Ugh...The answer's 75 cm yeah?

 

[nerdasdasd]

Looks like a maths in focus question ....

 

[AnimeX]

What's the answer? 242?

 

[anthony_wheels]

Looks like a maths in focus question ....

Yeah, I just had a look at it. Ch 8.9 Q16. It's not very well written, which is a bit unusual... :/
The answer is 74.7

 

[Menomaths]

Since it grows 2/5 of its previous height, it is the common ratio.
a(1-rⁿ/(1-r))
45(1-.4⁶/.6)
=74.7 cm

 

[AnimeX]

Since it grows 2/5 of its previous height, it is the common ratio.
a(1-rⁿ/(1-r))
45(1-.4⁶/.6)
=74.7 cm

Oh my bad, i got the 6th term