A box contains 20 crayons. There are 7 red crayons, 5 yellow crayons, and the rest are blue crayons. Suppose an experiment involves a person removing 3 crayons from the box. What is the probability that the person first removes a blue crayon, then a red crayon, and finally a yellow crayon, with replacement? State your answer as the exact percentage found.

18 units²

step-by-step explanation:

first let's find altitude bd using the distance formula

d = √((y₂ - y₁)² + (x₂ - x₁)²)

bd = √((0 - -3)² + (0 - 3)²)

bd = √18

given the placement of points a and c, we can denote that point d bisects segment ac.

we will call ac the base.

using the distance formula

ac = √((0 - 6)² + (-6 - 0)²)

ac = √72

knowing our base and our height, we can plug these into our triangle area formula

area = (b * h)/2

area = (√18 * √72) / 2

area = (√1296) / 2

area = 36 / 2

area = 18 units²