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# C2 GP

1. Find the number of terms in each of these geometric progressions

3,6,12,...,768 well i just want to know how to do this then ill know all of em
2. The general form of any term in a GP is , r is the term-to-term ratio, 2 in this case, and a must be 3.

So set 768 to the equation for the general form and solve for n. (n is the term number of the last term in the sequence.)
3. did that its not happening dont know how to get past that
4. So

You'll need to take logs to base 2. (Or any base for that matter but 2 is simpler.)

5. (Original post by Ganhad)
did that its not happening dont know how to get past that

Divide both sides by 3,

Now take logs.

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