Answer:
40% or 40/100 which reduces to 2/5
Step-by-step explanation:
total of 100 students
20 are studying both...
only geography : 50 - 20 = 30
only math : 40 - 20 = 20
geography + math + both + neither = 100
30 + 20 + 20 + x = 100
60 + x = 100
x = 100 - 60
x = 40....so 40 out of 100 students are studying neither geography or math.
P(neither math or geography) = 40/100 = 0.4 = 40% <==