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- jayhawk2001
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Total number of multiples of 9 = (3^5 - 3^4) / 9 + 1 = 18 + 1 = 19jamesk486 wrote:How many multiples of 9 are there between 3^4 and 3^5 (inclusive)?
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How many multiples of 9 are there between 3^4 and 3^5 (inclusive)?
3^4 = 3^2*3^2 = 9*9
3^5 = 3^2*3^2*3 = 9*9*3
How many multiples of 9 are between 81 and 243
81/9=9
243/9=27
Hence there are 27-9=18+1 (since both 81 and 243 are inclusive) = 19 multiples
Sorry for the rookie mistake....it's 243/9 and not 729/9...
3^4 = 3^2*3^2 = 9*9
3^5 = 3^2*3^2*3 = 9*9*3
How many multiples of 9 are between 81 and 243
81/9=9
243/9=27
Hence there are 27-9=18+1 (since both 81 and 243 are inclusive) = 19 multiples
Sorry for the rookie mistake....it's 243/9 and not 729/9...
Last edited by Cybermusings on Wed Apr 25, 2007 6:10 am, edited 1 time in total.