Make a proportion using the ratio (A:B) given and number of As and Bs really gotten in the class ()
Cross multiply
2 * 40 = 5 * A
80 = 5A
Isolate A by dividing 5 to both sides
80/5 = 5A/5
16 = A
If 40 people in the class got B's then 16 people got A's
Hope this helped!
~Just a girl in love with Shawn Mendes