At the museum, child admission is 5.80 and an adult is 9.20. On Saturday four times as many adults tickets as child tickets were sold, for a total sales of 1320.60. How many child tickets were sold that day?

Number of child tickets sold = 31

Step-by-step explanation:

Let,

x be the number of child tickets sold

y be the number of adult tickets sold

According to given statement;

y = 4x      Eqn 1

5.80x + 9.20y = 1320.60     Eqn 2

Putting y=4x in Eqn 2

5.80x + 9.20(4x) = 1320.60

5.80x + 36.80x = 1320.60

42.60x = 1320.60

Dividing both sides by 42.60

Hence,

Number of child tickets sold = 31

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.