A class of 6 boys and 12 girls are preparing for finals. The teacher is going to select 3 students to be exempt from the test. What is the probability that the three students that are exempt will be all boys?

Step-by-step explanation:

Given:

In a class:

Number of boys = 6

Number of girls = 12

The teach has to select 3 students to be exempted from the test.

To find the probability that all boys students are exempted from the exam.

Solution:

Total number of students in the class =

Number of ways to select 3 students among 18 from the class can be given =

Total number of boys = 6

Number of ways to select 3 students among 6 boys can be given =

So, the probability of selecting all 3 students as boys can be given as =

⇒

⇒

⇒  (Answer)

lo.lll

step-by-step explanation:

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.