In Jan's library, she has 24 informational books. If 15% of the books are informational text, how many total books are in her library?

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?

We just started the introduction into circles and i have no idea how to do this.

According to the general equation for conditional probability if p(anb)=3/7 and p(b)=7/8 what is p(a i b)