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 
Sum divided by count. Add up all the numbers and divide it by how many numbers it is.
3+(-4)=(-1)
so, 3 is the missing number
Answer:
1
Step-by-step explanation:
Answer:
B.
Step-by-step explanation:
You have to use the number in the variable to figure out if the number multiplied by 3.5 goes over 20 dollars. The highest you can go without going over 20 dollars is 5 notebooks