Answer:
20*(4/5)
Step-by-step explanation:
The expression you will use is :
20*(4/5) = 80/5 = 16
16 is 80 percent of 20 wich equals 4 fifths that's true
This is the full question:
This month, Judy has checked out 20 books from the library, and 4/5 of them were biographies. Which expression can be used to betermin the number of brographies Judy checked out?
Choices are here:
A. 20 divide by 4/5
B. 20 x 4/5
C. 4/5 divide by 20
D. 5/4 divide by 20
The answer is: the choice B. 20 × 4/5
Explanation:
You are told that the total number of books checked is 20 and that from them the fraction 4/5 were biographies.
A fraction is a ratio, and that ratio is equal to the ratio of biographies to the total number of book. That is what is called a proportion.
You can write the proportion in this way:
4 number of biographies checked
----- = -------------------------------------------------
5 total number of books checked
The number of biographies checked is the unknown. Call it x
The total number of books checked is 20.
So the proportion is:
4 x
---- = ------
5 20
And applying equallity properties that drives to:
x = 20 * 4/5.
Which is the answer to the question.
