Lou has the first 4 encyclopedias lined up on a shelf, A, B, C, and D. If he picks two at random, what is the probability that he picks A first and B second?

A) 1/24 B) 1/6 C) ½ D) 1/12

D

Step-by-step explanation:

Given:

Lou has the first 4 encyclopedias lined up on a shelf, A, B, C, and D.

To find: probability that he picks A first and B second if he picks two at random

Solution:

Total number of outcomes =

Favourable outcomes are ABCD, ABDC

Number of favourable outcomes = 2

probability that he picks A first and B second = Number of favourable outcomes / Total number of outcomes =

to rewrite a literal equation you may need to divide by a number, or by a variable.

hope i .

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.