4/29/10

Test 3 Section 5 - #16 (page 530)

Well, according to the way the problem is set up, we're going to have one "1", two "2"'s, three "3"'s, etc.  We want to know when the first "12" will come.  Well, that's going to come after the eleventh "11".  Let's just count up how many terms will come first:

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 = 66

So if 66 terms come before the first "12", the first "12" will be the 67th term.

2 comments:

  1. i don't understand i thought that every number is being repeated by it's no. like for an example 1 is written 1 time 2 is written two times then 12 should be written 12 times that's what i understood from the question and obviously what i've got from the question is incorrect so please can you help me more with understanding it with a different method than that one thanks a lot i would really appreciate it if you would answer my SAT is tomorrow and I'm already panicking

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    Replies
    1. No, you understand it right. When does the first 12 come? It comes after 1 1, 2 2s, 3 3s, 4 4s, 5 5s, etc. The first 12 will be after 1 + 2 + 3 + ... + 11 terms.

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