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Sheet # 49 Critical Thinking

Name: _____________________ Date_____________


Show and explain your work. Draw pictures or make tables to explain your answer.

One person makes 2 telephone calls to 2 people and tells them a secret. Then each of these people tells 2 other persons over the phone. Suppose this continues and each telephone call lasts 1 minute.

a) How long will it take for 250 people to know the secret?












b) If What if one person tells 3 people , they in turn tell 3 more people, and so on? How long will it take for 250 people to know the secret?


















Answer for sheet # 49

a)

Round # People Informed Time spent (minutes)
1 2 2
2 2 x 2 = 4 2 (parallel phone calls)
3 4 x 2 = 8 2
4 16 2
5 32 2
6 64 2
7 128 2
8 256 2

It will take about 15 to 16 minutes to contact over 256 people


b)
Round # People Informed Time spent (minutes)
1 3 3
2 3 x 3= 9 3 (parallel phone calls)
3 27 3
4 81 3
5 243 3
I t will take about 12 to 13 minutes to reach 256 people.