find the number in the pattern

[justnkade]

5, 15, 45, ?, 405, ?, 3645...What are the missing numbers? and What is the rule?

I have no clue as to where to start...I don't want the answer..just a shove in the right direction.

Thanks!

 

[Deleted member 4993]

5, 15, 45, X, 405, ?, 3645...What are the missing numbers? and What is the rule?

I have no clue as to where to start...I don't want the answer..just a shove in the right direction.

Thanks!

How much is:

\(\displaystyle \frac{15}{5}\)

How much is:

\(\displaystyle \frac{45}{15}\)

What do you think

\(\displaystyle \frac{X}{45} \ = \ ?\)

and

\(\displaystyle \frac{405}{X} \ = \ ?\)

And continue.....

 

[BigGlenntheHeavy]

\(\displaystyle a_n \ = \ a_1r^{n-1}\)

 

[justnkade]

ok...15/5=3.......45/15=3

or multiply each one by 3....5x3=15.....15x3=45....45x3=135....135x3=405...405x3=1215.....1215x3=3645

5,15,45,135,405,1215,3645

Thanks!

This is my 4th graders math problems...I'm trying to help him and have no idea where to start...BTW..I'm not giving him the answers...I'm making him figure it out..

Thanks, Thanks so much!!!