a) 2
b) 3
c) 10
d) 5
total discs are 25
15 have neither Paul or Art
25-15 = 10 have at least one of Paul or Art = c)
5 have both, 10-5 = 5 have at most one of the two = d)
which also = a) + b) = 2+3 =5
a) = 7-5 = 2
b) = 8-5 = 3
draw two overlapping circles. the overlap = 5
the two circles are inside a rectangle, the area between the circles and the rectangle is 15
the two circles have 10 discs, 5 are the overlap, 5 are just one of each, Art or Paul