Question

The incomplete table below summarizes the number of left-handed students and right-handed students by gender for the eighth grade students at Keisel Middle School. There are 6 times as many right-handed female students as there are left-handed female students, and there are 8 times as many right-handed male students as there are left-handed male students. if there is a total of 18 left-handed students and 130 right-handed students in the school, which of the following is closest to the probability that a right-handed student selected at random is female? (Note: Assume that none of the eighth-grade students are both right-handed and left-handed.)

A) 0.857
B) 0.878
C) 0.331
D) 0.323
(Table is just total number of left handed females + males =18 and total number of right handed females + males=130)

Answer 1

let m be the number of left-handed males , and f be the number of left-handed females

m + f = 18 ... 8m + 8f = 144

8m + 6f = 130

subtracting (to eliminate m) ... 2f = 14

find number of right-handed females

find fraction of right-handed students that are female