A teacher is lining up her class for a class picture. Jackson, William, and Rowan are best friends in the class. If there are 18 children in her class, what is the probability that Jackson is first, William is second, and Rowan is last?

1/4896

Step-by-step explanation:

This is a permutation problem, where order matters.

There are 18! ways to line up the class, and (18−3)!=15! ways where three children line up first, second, and third.

Then the probability is

P=15!18!=14896≈0.0002

answer:   28.56 feet (approx)

step-by-step explanation:

since, triangle abc has measure of angle c equal to 55 degrees, measure of angle abc equal to 90 degrees, and length of bc equal to 20 feet.

we have to find out the measurement of segment ab.

therefore, tan 55° =

but bc = 20 feet.

⇒ tan 55 ° =  

⇒ ab = 20 × tan 55 °

⇒ ab = 20 × 1.42814800674

⇒ ab = 28.5629601348   ≈ 28.56 feet

i think the answer is b