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pb_india
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A code is defined to be a sequence of three different 11 Jan 2005, 09:00
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A code is defined to be a sequence of three different numbers chosen from 1 to 9, the first cannot be 0 or 1, the second must be either 0 or 1, the second and the third cannot be both 0. How many such codes exist?



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Paul
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A code is defined to be a sequence of three different 11 Jan 2005, 09:05
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pb_india
A code is defined to be a sequence of three different numbers chosen from 1 to 9, the first cannot be 0 or 1, the second must be either 0 or 1, the second and the third cannot be both 0. How many such codes exist?
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Should the first sentence not be: A code is defined to be a sequence of three different numbers chosen from 0 to 9
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pb_india
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A code is defined to be a sequence of three different 11 Jan 2005, 09:07
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Paul, yes. it is 0..9
Sorry for the typo.
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rxs0005
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A code is defined to be a sequence of three different 11 Jan 2005, 09:14
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I am gettgin 792

whats the OA

thanks
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pb_india
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A code is defined to be a sequence of three different 11 Jan 2005, 09:19
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Just don't post the answer.. Can you post how you got to the final number?

I will post OA in some time.
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rthothad
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A code is defined to be a sequence of three different 11 Jan 2005, 09:24
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152
When the second term is 0: 8 * 1 * 9 = 72
When the second term is 1: 8 * 1 * 10 = 80
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A code is defined to be a sequence of three different 11 Jan 2005, 09:34
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oops. i took its 9 numbers in all.. and also.. didn't read hte last half where cannot have two 0's together..
without that.. tis 152?
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A code is defined to be a sequence of three different 11 Jan 2005, 12:22
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A code is defined to be a sequence of three different numbers chosen from 1 to 9, the first cannot be 0 or 1, the second must be either 0 or 1, the second and the third cannot be both 0. How many such codes exist?


When the second term is 0: 8 * 1 * 9 = 72
When the second term is 1: 8 * 1 * 10 = 80

rthotad ... your answer is right but the question says three different numbers
so the scope for second and third cannot be 0 doesn't exist.

Is the question right?
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A code is defined to be a sequence of three different 11 Jan 2005, 12:33
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Vijo, I am not sure if I get what you are trying to get at but the question seems to be good.
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greenandwise
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A code is defined to be a sequence of three different 11 Jan 2005, 13:22
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Good question...I just have a quick coneptual question...when do you know when to multiply the various outcomes or add them...I always have a problem with this....so what I mean is in this case we addded the 72 possibilities with 80 posiiblities to get 152 but under what circumstances do you multiply them...

I appreciate your help!



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