Question

in a group of 30 students,20 are male,15 are from southern region,9 from the central and 6 from the north.if the proportion of female students is the same for each region,how many students are either female or from the central{or both}A.9 B.10 C14 D.16 E.19

Answer 1

since 2/3 of the students are male, that means that 2/3 of each region are male.

1/3 of each region are female, meaning that there are

9 students from central
5 female from south
2 females from north

16 are female or from central. (D)