Russell, a seventh grader, finds out the winner of the school talent show at 4:00pm on Friday. He calls two seventh grade friends at 4:15pm to tell them. By 4:30pm they each call two 7th grade friends. If each person who is called calls two more 7th graders every fifteen minutes, when will all 176 seventh grade students know the winner?
+130466 Note the pattern here.......
20 = 1 person knows at 4:15
21 = 2 more people know at 4:30
22 = 4 more people know at 4:45
23 = 8 more people know at 5:00
.......and note that the sum of the previous terms is always one less than the last term. Therefore 63 + 26 = 63 + 64 = 127. This implies that, starting at 4:15 PM ......6 "blocks" of 15 minutes (= 90 minutes) are necessary to notify 127 students. So, by 5:45 PM, 127 students are notified. This means that one more 15 minute block will be necessary to notify all 176 students = 6:00 PM
+130466 Note the pattern here.......
20 = 1 person knows at 4:15
21 = 2 more people know at 4:30
22 = 4 more people know at 4:45
23 = 8 more people know at 5:00
.......and note that the sum of the previous terms is always one less than the last term. Therefore 63 + 26 = 63 + 64 = 127. This implies that, starting at 4:15 PM ......6 "blocks" of 15 minutes (= 90 minutes) are necessary to notify 127 students. So, by 5:45 PM, 127 students are notified. This means that one more 15 minute block will be necessary to notify all 176 students = 6:00 PM
