There is a 3/10, or 30% chance that she pulls a math book out first and a chemistry book out second.
(2 + 3) = 5 books total. This means 2/5 are chemistry and 3/5 are math. If she pulls one book out, then another… it means she’ll have one less book to grab from. This is represented by: (3/5)x(2/4)= 3/10
