Christian made a list of five different kinds of brownies: chocolate chip brownies, Rocky Road brownies, brownies with walnuts, peanut butter swirl brownies, and butterscotch brownies. He asked seventy-eight students to choose their favorite brownie from the last. 8/39 of the students liked peanut butter swirl brownies the best. Three-thirteenths of the students preferred Rocky Road brownies. Chocolate chip brownies were the favorite of two-thirteenths of the students. 7/39 of the students just loved brownies with walnuts and the rest of the students liked butterscotch brownies best. How many students preferred butterscotch brownies?
Christian made a list of five different kinds of brownies: chocolate chip brownies, Rocky Road brownies, brownies with walnuts, peanut butter swirl brownies, and butterscotch brownies. He asked seventy-eight students to choose their favorite brownie from the last. 8/39 of the students liked peanut butter swirl brownies the best. Three-thirteenths of the students preferred Rocky Road brownies. Chocolate chip brownies were the favorite of two-thirteenths of the students. 7/39 of the students just loved brownies with walnuts and the rest of the students liked butterscotch brownies best. How many students preferred butterscotch brownies?
Convert each fraction so that they all have a common denominator
peanut butter 8 / 39 = 16 / 78
rocky road 3 / 13 = 9 / 78
chocolate chip 2 / 13 = 6 / 78
brownies 7 / 39 = 14 / 78
total fraction of students who did not prefer butterscotch 45 / 78 => 45 students
total number of students who did prefer butterscotch 78 – 45 = 33 students
.
No. of students liking peanut butter swirl brownies
= 8/39 = 16/78 = 16 students
No. of students liking Rocky Road brownies
= 3/13 = 18/78 = 18 students
No. of students liking chocolate chip brownies
= 2/13 = 12/78 = 12 students
No. of students liking brownies with walnuts
= 7/39 = 14/78 = 14 students
No. of students liking butter scotch brownies
= 78 - (16 + 18 + 12 + 4)
= 18 students