Help!!!! C2 geometric sequences

I've done question 1a and 1b, but I don't seem to be getting the right answer for questions 1c.
To get 1c I did 242(1.1)^2
I get 292.82. The answer says 266! What am I doing wrong? Please help

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Reply 1

BananaPie

200x(1.1)^3 = 266.2

= 266 ants

Reply 2

Indeterminate

3

Original post by Pilot96

I've done question 1a and 1b, but I don't seem to be getting the right answer for questions 1c.
To get 1c I did 242(1.1)^2
I get 292.82. The answer says 266! What am I doing wrong? Please help

Posted from TSR Mobile

After n years, the number of ants is given by

\displaystyle 200 \times (1.1)^n

Reply 3

Pilot96

OP

Original post by BananaPie

200x(1.1)^3 = 266.2

= 266 ants

But don't you use the equation ar^n-1??

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Reply 4

Kvothe the Arcane

20

Original post by Pilot96

But don't you use the equation ar^n-1??

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the key word is 'after' so 3 years after the initial, n=4. Therefore n-1=3

Reply 5

Johnathon16

1

I'm doing the same spec as you and if you are struggling with this or anything else in the specification you should try www.examsolutions.net
it's really helpful tutorials on everything and has past exam papers. This website has really helped me in this course, give it a look

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Reply 6

Pilot96

OP

Original post by Johnathon16

I'm doing the same spec as you and if you are struggling with this or anything else in the specification you should try www.examsolutions.net
it's really helpful tutorials on everything and has past exam papers. This website has really helped me in this course, give it a look

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Thank you so much!!!

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