At a pizza shop, 70% of the customers order a pizza, 25% of the customers order a salad, and 15% of the customers order both a pizza and a salad. if a customer is chosen at random, what is the probability that he or she orders either a pizza or a salad?

The probability that a randomly selected customer orders a pizza or a salad is 80%

Step-by-step explanation:

Let's call

= the proability of someone asking for a pizza

= the probability that a customer orders a salad

Pp∩s = the probability that a customer orders a pizza and a salad.

We know from the statement of the problem that:

= 70% = 0.7

= 25% = 0.25

Pp∩s = 15% = 0.15

We want to know the probability that a randomly selected customer will order a pizza or a salad. Then, by set theory, that probability is calculated as:

Pp∪s = ∪ - Pp∩s

So:

Pp∪s = Pp + Ps - Pp∩s

 Where Pp∪e is the probability that the customer orders a pizza or a salad, but not both at the same time.

Pp∪e = 0.7 + 0.25 -0.15

Pp∪e = 0.8

Finally, the probability that a randomly selected customer orders a pizza or a salad is 80%

step-by-step explanation:

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form