JAMB - Mathematics (1997 - No. 8)
A survey of 100 students in an institution shows that 80 students speak Hausa and 20 students speak Igbo, while only 9 students speak both language. How many students speak neither Hausa nor Igbo?
0
9
11
20
คำอธิบาย
Let the number of students that speak Hausa and Igbo be represented by H and I respectively.
n(H only) = 80 - 9 = 71.
n(I only) = 20 - 9 = 11.
n(neither H nor I) = 100 - (71 + 9 + 11)
= 100 - 91 = 9 students.