A librarian put 42 books back on the shelves before lunch. Of the books, 14 were non-fiction. What is the ratio of the number of non-fiction books to the total number of books the librarian put away before lunch?

Non fiction : Total number of books

= 14 : 42

= 1:3

Step-by-step explanation:

Total number of books = 42 books

Non fiction books = 14 books

The ratio of the number of non-fiction books to the total number of books is :

Non fiction : Total number of books

= 14 : 42

Further simplified

= 1:3

delaney would like to make a 5lb nut mixture that is 60% peanuts and 40% almonds.

she has several pounds of peanuts and several pounds of a mixture that is 20% peanuts and 80% almonds.

let 'p' represent the number of pounds of peanuts needed to make the new mixture, and  

let 'm' represent the number of pounds of the 80% almond-20% peanut mixture.

:

p + m = 5

therefore

m = (5-p)

write an equation based on the percent of peanuts

1p + .2m = .6(5)

replace m with (5-p)

p + .2(5-p) = .6(5)

p + 1 - .2p = 3

p - .2p = 3 - 1

.8p = 2

p = 2/.8

p = 2.5 lbs of peanuts required

then

5 - 2.5 = 2.5 lbs of the peanut/almond mixture required

:

a) what is the system that models this situation?

p + m = 5

1p + .2m = .6(5)