Mathematics 2011 JAMB Past Questions - Question 11: Ralia has 7 different poster to be hung in her bedroom ,living room and kitchen .Assuming she has plans to place at least ,a poster in each of the 3 room ,how many choices does she have ?

Correct Answer

D

Explanation

The first poster has 7 ways to be arraigned in 6 ways to be arriaged in 6 ways and the third poster in 5 ways.= 7 x 6 x 5 = 210 ways7 / psub3 = 7! /(7-3)! = 7! / 4!= 7 x6 x5 4! / 4!= To calculate the number of choices Ralia has for hanging the posters, we can use the concept of combinations.Since Ralia wants to place at least one poster in each of the three rooms (bedroom, living room, and kitchen), we can consider this as selecting one poster for each room first.For the bedroom, Ralia has 7 choices.For the living room, Ralia has 6 choices (since one poster has already been chosen for the bedroom).For the kitchen, Ralia has 5 choices (since two posters have already been chosen for the bedroom and living room).To find the total number of choices, we multiply the number of choices for each room:Total choices = 7 * 6 * 5 = 210Therefore, Ralia has 210 choices for hanging the posters in her bedroom, living room, and kitchen.