20 books are divided parcels, each parcel contains one fifth of the total. If a librarian wants to buy 16 books how many fifths should he take?

x=4

Step-by-step explanation:

1/5 of the total= 1 parcel= 1/5 of 20= 4

So one parcel is 4 books

Then you can set up an equation 16=4x where x = number of parcels.

4x = 16

4x/4 = 16/4

x=4

every 5 customers that walk in, only 2 buy popcorn.

step-by-step explanation:

basically 2/5.

brainliest would be appreciated.

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.