help! |
 Dec 7 2004, 11:31 PM
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 jellyfishing, jellyfishing  Group: Member Posts: 1,174 Joined: Oct 2004 Member No: 55,185  |
aaacch i don't get this math problem, i'm really stupid. it's a junior high problem, so maybe someone could help?
Claire finished her assignment early, so her teacher suggested that she find the last digit of the product 3 x 3 to third power x 3 to fifth......x 3 to nineteenth. The entire product was too big for her calculator, but she still found the last digit. What is the last digit? Explain how she determined her answer i know that if you add all the exponents, you'll get 3 to the 100th power, since 3+5+7+9+11+13+15+17+19=100 right (those are the exponent values...), so it'd be 3 to the 100th power. on my calc i got 5.153775207 to the 47th power.....what next?!?!!? sorry if this is in the wrong board...i saw someone ask for math help awhile back, so i figured it'd be OK 
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Dec 8 2004, 02:16 AM
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 :hammer: Group: Staff Alumni Posts: 9,849 Joined: Mar 2004 Member No: 7,700 |
QUOTE(pAtRiCk_sTar @ Dec 7 2004, 11:02 PM) ooooh i think i see what you're saying. so the 3 to the 100th power ends with a one right? but did you just write it all out or use some sort of technique?? If the exponenent is divisble by 4, then the last digit will be 1. In this case, 100 is divisible by 4, and therefore the last digit of 3^100 is 1. |
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Posts in this topic
pAtRiCk_sTar help! Dec 7 2004, 11:31 PM
Spirited Away QUOTE5.153775207 to the 47th power.....what next?... Dec 7 2004, 11:41 PM DaTru KataLYST do you mean to find the last digit of the product ... Dec 7 2004, 11:44 PM Spirited Away This page has something similar except with the nu... Dec 7 2004, 11:47 PM x_angawhomps I think the last digit is going to be 1.
Because... Dec 8 2004, 12:20 AM pAtRiCk_sTar oooh thanks, i get it now! Dec 8 2004, 01:15 AM jr0h im sick of math problems..sorry. hahah Dec 8 2004, 01:20 AM pAtRiCk_sTar wait, wouldn't the pattern alternate between 3... Dec 8 2004, 01:41 AM Spirited Away It alternates between 1, 3, 9, 7. Just use a calcu... Dec 8 2004, 01:43 AM DaTru KataLYST omg, you guys...i'm lost...=( why must math be... Dec 8 2004, 01:53 AM pAtRiCk_sTar QUOTE(uninspiredfae @ Dec 7 2004, 10:43 PM)It... Dec 8 2004, 02:02 AM pAtRiCk_sTar QUOTE(x_angawhomps @ Dec 7 2004, 11:16 PM)If ... Dec 8 2004, 02:30 AM angel-roh it would be so cool if we had a homework help foru... Dec 9 2004, 12:16 AM
Just_Dream Problem solved.
TOPIC CLOSED. Dec 9 2004, 12:19 AM |
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