Pls answer quick ive got 2 minutes left

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?

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

What is the volume of a cone with a height of 6 cm in the radius of 2 cm