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

let y equal to

the total fare and x is the mile of taxi ride. so the equation is

y = 0.55x + 1.75

since susie has

$10 to spend for a taxi cab, so he can have

10 = 0.55x +

1.75

x = 15 miles of

taxi ride

so the system of

inequality is

10 < 0.55x +

1.75

x > 2