# Probability question... simple sampling.

#### math951

For (B), I am getting 2/6... how did textbook come up with 4/7?

#### Plato

MHF Helper
View attachment 39539
For (B), I am getting 2/6... how did textbook come up with 4/7?
How many friends does she have totally?
Of those, how many are at a restaurant with another of her friends?

#### math951

She has 6 friends in total.
Those at a restaurant with another of her friends are 2.

#### math951

So the denominator just includes her at the restaurant now, okay. I see

#### Plato

MHF Helper
She has 6 friends in total.
Those at a restaurant with another of her friends are 2.
NO! She has seven friends: $1+1+1+2+2=7$

#### math951

Woops..understand now lmao