P(not 2 consecutive times)

[nycmath]

A bag has 20 green marbles and 45 blue marbles. What is the probability of NOT randomly selecting 2 blue marbles?

[Eigenvalue]

P(blue)=[tex]\frac{45}{65}[/tex]=[tex]\frac{9}{13}[/tex]

With replacement
P(not blue twice)=1-(P(blue)*P(blue))
=1-([tex]\frac{9}{13}[/tex])²

=[tex]\frac{169-81}{169}[/tex]

=[tex]\frac{88}{169}[/tex]

Without replacement:
P(not blue twice)=1-(P(blue)*P(blue))
=1-([tex]\frac{45}{65}[/tex]*[tex]\frac{44}{64}[/tex])

=1-[tex]\frac{9*11}{13*16}[/tex]

=[tex]\frac{109}{208}[/tex]

[nycmath]

P(blue)=[tex]\frac{45}{65}[/tex]=[tex]\frac{9}{13}[/tex]

With replacement
P(not blue twice)=1-(P(blue)*P(blue))
=1-([tex]\frac{9}{13}[/tex])²

=[tex]\frac{169-81}{169}[/tex]

=[tex]\frac{88}{169}[/tex]

Without replacement:
P(not blue twice)=1-(P(blue)*P(blue))
=1-([tex]\frac{45}{65}[/tex]*[tex]\frac{44}{64}[/tex])

=1-[tex]\frac{9*11}{13*16}[/tex]

=[tex]\frac{109}{208}[/tex]

This is a good mechanical reply but you don't explain what information in the word problem led to the right setup to find the correct answer.