document.write( "Question 559457: The Greek God Zeus ordered his blacksmith Hephaestus to create a perpetual water-making machine to fill Zeus' mighty chalice. The volume of Zeus' chalice was reported to hold about One hundred and fifty sextillion gallons (that is a fifteen followed by twenty-two zeros). If Hephaetus' machine pours out 2 gallon in the first minute and then doubles its output each minute, find in
\n" ); document.write( "which minute would this hypothetical machine pour out a single quantity of water that would be enough to fill Zeus' chalice with water?\r
\n" ); document.write( "\n" ); document.write( "put in minutes
\n" ); document.write( "i only get the \"15%2A10%5E22\" I dont know how to set this problem up to solve as my logrithmic knowledge is minor\r
\n" ); document.write( "\n" ); document.write( "Help will be greatly appreciated
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Algebra.Com's Answer #363435 by htmentor(1343)\"\" \"About 
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The Greek God Zeus ordered his blacksmith Hephaestus to create a perpetual water-making machine to fill Zeus' mighty chalice. The volume of Zeus' chalice was reported to hold about One hundred and fifty sextillion gallons (that is a fifteen followed by twenty-two zeros). If Hephaetus' machine pours out 2 gallon in the first minute and then doubles its output each minute, find in
\n" ); document.write( "which minute would this hypothetical machine pour out a single quantity of water that would be enough to fill Zeus' chalice with water?
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\n" ); document.write( "First, consider how much water is added to the chalice each minute.
\n" ); document.write( "During the 1st minute, there are 2 gallons added to the chalice
\n" ); document.write( "During the 2nd minute, there are 4 gallons added
\n" ); document.write( "During the 3rd minute, there are 8 gallons added, etc.
\n" ); document.write( "The number of gallons added for each successive minute consists of a geometric sequence: 2,4,8,16,...
\n" ); document.write( "To determine how long it takes to fill the chalice, we need to sum this sequence
\n" ); document.write( "The sum of a geometric sequence with common ratio r is:
\n" ); document.write( "S(n) = a(1-r^n)/(1-r) where a = the first term
\n" ); document.write( "In this case a = 2 and r = 2:
\n" ); document.write( "S(n) = 2(1-2^n)/(1-2) = 2(2^n - 1) = 15*10^22
\n" ); document.write( "We need to solve for n:
\n" ); document.write( "2^n - 1 = 7.5E22 [Scientific notation]
\n" ); document.write( "2^n = 7.5E22 + 1
\n" ); document.write( "Take the logarithm of both sides:
\n" ); document.write( "n*log(2) = log(7.5E22 + 1)
\n" ); document.write( "n = 22.875/0.301 = 75.997 min., so the chalice gets filled in the 76th minute
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