Answer:
Negative Binomial
Step-by-step explanation:
The girl receives only 5% of mail which are addressed to her. Rest of 95% mails belong to other family members.
P (X) = 5%
P (X) = 95 / 5
P (X) = 19
The family receives 19 mails out of which only 5% will address the girl. The all other mails belong to the other family members.
Answer:
9
Step-by-step explanation:
3/8 x 24 = 9
24 / 8 = 3
3 x 3 = 9
Let, the total number of students in school that ride the bike to school be "x"
Now,
Using ratio and proportion, we get,





So, out of 800 students, 125 ride their bike to school.
Answer:

Step-by-step explanation:
In probability,
"AND" means "multiplication"
"OR" means "ADDITION"
We want probability of Blue Pen and Yellow Highlighter. So we find individual probabilities and "MULTIPLY" them.
Let P(b) be probability of blue pen
Let P(y) be probability of yellow highlighter
We know probability of event is that event divided by total number of that
So,
There are 4 + 2 = 6 pens
Blue pen = 2
Hence,
P(b) = 2/6 = 1/3
And,
There are 5 highlighters
Yellow highlighter = 1
Hence,
P(y) = 1/5
Now,
P(b and y) = 1/3 * 1/5 = 1/15
Hence,
probability of grabbing blue pen and a yellow highlighter is 