Need help w this thanks

Galen sold tickets of his church’s carnival for a total of $2,820. children’s tickets cost $3 each and adult tickets cost $5 each. the number of children’s tickets sold was 30 more than 3 times the number of adult tickets slod. how many children’s ticket and how many adult tickets did he sell?

When 142 is added to a number the result is 64 more times the number my options are 35 37 39 41

Find the arc length of the semicircle. 7the grade