3) A drawer contains 10 blue pens, and 10 red pens. Without looking, Mrs. Stanton is going to take one pen from a drawer, use it, and then put it back in
the drawer. Then he is going to take another pen from the drawer to use. What
is the probability of Mrs. Stanton taking a red pen first and then taking a blue
pen? P(red, then blue)?

25%

it's 50-50 for drawing a certain color pen each time.

so, the odds of drawing a red pen on the first draw is 50%

the odds of drawing a blue pen on the second draw is also 50%

so, to to *both* in order is 50% of 50%- or 25%

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b

walter needs to make at least 5 more cookies but no more than 40. 5 ≥ x ≥ 40;

step-by-step explanation:

walter has to make a minimum of 20 cookies. he already has 15 cookies made, so he must make 5 more to meet the minimum.

the maximum amount of cookies he can make is 55. he already has 15, so he has to make no more than 40 more cookies to meet the maximum.