Ex 2.3, 2

Transcript

Ex 2.3, 2 A rally starts with 120 members. Each hour, 9 members drop out of the group. How many members will remain after 1, 2, 3, … hours? Find a linear expression to represent the number of members at the end of the nth hour. Given that Initial members = 120 Members dropping out every hour = 9 So, we can find out Number of members after 1st, 2nd, 3rd, 4th hour as Number of members after 1st hour = Initial members – Number of members dropping out = 120 – 9 = 111 Number of members after 2nd hour = Initial members – Number of members dropping out × 2 = 120 – 9 × 2 = 120 – 18 = 102 Number of members after 3rd hour = Initial members – Number of members dropping out × 3 = 120 – 9 × 3 = 120 – 27 = 93 Thus, we can find Number of members after nth hour as Number of members after nth hour = Initial members – Number of members dropping out × n = 120 – 9 × n = 120 – 9n