31. I'm not positive but give it a shot if it is wrong message me back!
Answer:
25 child tickets were sold on Monday.
Step-by-step explanation:
Cost of ticket for a child = $5.10
Cost of ticket for an adult = $9.70
Let the number of child tickets sold be x.
Number of an adult tickets sold = 2x
Total sales on tickets = $612.50
[tex]2x\times \$9.70+x\times \$5.10 =\$612.50[/tex]
[tex]24.5x=612.5[/tex]
[tex]x=\frac{612.5}{24.5}=25[/tex]
25 child tickets were sold on Monday.