The National Association for Women in Science asked recent high school grads if they had taken certain science classes. Of those surveyed, 28 said they had taken physics, 47 said they had taken chemistry and 13 said they had taken both. Twelve said they had taken neither. How many recent high school grads were surveyed?

Solution:

Number of recent high school grads who were surveyed =

28 + 47 -13 +12 = 74

so 74 recent high school grads were surveyed.