At the city museum, child admission is

$5.40
and adult admission is
$8.70
. On Thursday, three times as many adult tickets as child tickets were sold, for a total sales of
$693.00
. How many child tickets were sold that day?

693=A*8.7+C*5.4

but C=3A

solve for A, and C

27.83

Let's assume the number of child tickets sold is "x".

According to the given information, the number of adult tickets sold on Thursday was three times the number of child tickets sold, i.e., 3x.

The cost of each child ticket is $5.40, so the total revenue from child tickets is 5.40x.

The cost of each adult ticket is $8.70, so the total revenue from adult tickets is 8.70 * 3x = 26.10x.

The total sales for that day is $693.00, so we can write the equation:

5.40x + 26.10x = 693.00

Combining like terms, we get:

31.5x = 693.00

To solve for x, we can divide both sides of the equation by 31.5:

x = 693.00 / 31.5

x ≈ 22

Therefore, approximately 22 child tickets were sold that day.

To solve this problem, let's assign variables to the unknowns. Let's say that the number of child tickets sold is represented by "C" and the number of adult tickets sold is represented by "A".

Given information:
- Child admission price: $5.40
- Adult admission price: $8.70
- Total sales amount: $693.00
- On Thursday, three times as many adult tickets as child tickets were sold

We can set up the following equations based on the given information:

1) C x $5.40 + A x $8.70 = $693.00 (equation for total sales)
2) A = 3C (equation for three times as many adult tickets as child tickets)

To find the value of C, we need to substitute the value of A from equation 2 into equation 1.

Substituting A = 3C into equation 1:

C x $5.40 + 3C x $8.70 = $693.00

Now, we can simplify the equation:

5.40C + 26.10C = 693.00
31.50C = 693.00

To isolate C, divide both sides of the equation by 31.50:

C = 693.00 / 31.50
C = 22

Therefore, 22 child tickets were sold that day.