What is the probability that a randomly selected reference book is hardcover? 0.25 0.4 0.6 0.75

0.4

Step-by-step explanation:

 The correct option is (B) 0.4.

Step-by-step explanation:  We are given to find the probability that a randomly selected reference book is hardcover.

Let, S denote the sample space for the experiment of selecting a book.

Then, n(S) = 60.

Let A denote the event that the selected book is is a reference one and B denote the event that the selected book is a hardcover.

Then, according to the given information, we have

So,

Therefore, the probability that a randomly selected reference book is hardcover is equal to the conditional probability of event B given A.

That is, the required probability is

Option (B) is correct.

26 is 33.33% of 78

step-by-step explanation:

26 is what percent of 78?

26 is p% of 78

equation: y = p% * x

solving our equation for p

p% = y/x

p% = 26/78

p = 0.3333

convert decimal to percent:

p% = 0.3333 * 100 = 33.33%

answer is c

step-by-step explanation:

81/12=324/x

x=48