document.write( "Question 1141419: Could someone please help me I've tried like 5 times and keep getting the wrong answer.
\n" ); document.write( "Suppose you drop a ball from a window 15 meters above the ground. The ball bounces to 60% of its previous height with each bounce. What is the total number of meters (rounded to the nearest tenth) the ball travels between the time it is dropped and the 10th bounce?\r
\n" ); document.write( "\n" ); document.write( "A 37.3 meters
\n" ); document.write( "B 378.6 meters
\n" ); document.write( "C 59.5 meters
\n" ); document.write( "D 63.4 meters \n" ); document.write( "
Algebra.Com's Answer #761985 by Edwin McCravy(20059)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "You may have made your mistake because you didn't take into account that the\r\n" );
document.write( "ball drops one more time than it rises.  The second solution above is correct,\r\n" );
document.write( "but you may not have studied the infinite geometric series, since your problem\r\n" );
document.write( "stops at the 10th bounce.\r\n" );
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document.write( "If D represents a downward drop of the ball and U represents a upward bounce\r\n" );
document.write( "of the ball, then the ball's path goes DUDUDUDUDUDUDUDUDUD.  Break it up as: \r\n" );
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document.write( "D UD UD UD UD UD UD UD UD UD\r\n" );
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document.write( "The initial D is 15 meters. So let's keep that separate and add it in after\r\n" );
document.write( "we've calculated the other distances the ball travels, which is\r\n" );
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document.write( "   UD UD UD UD UD UD UD UD UD\r\n" );
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document.write( "After the first \"D\", the ball does only 9 more \"UD\"'s.\r\n" );
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document.write( "The very first time the ball goes upward, it goes up 60% of 15 meters or 9\r\n" );
document.write( "meters.\r\n" );
document.write( "Then it drops 9 meters so that means the first total \"UD\" is 9+9=18 meters. \r\n" );
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document.write( "So the geometric series has first term a1 = 18 meters and common ratio r = 60%\r\n" );
document.write( "or r = 0.6\r\n" );
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document.write( "The formula for the sum of a geometric series with n=9, a1=18 and r=0.6 is\r\n" );
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document.write( "\"S%5Bn%5D=a%5B1%5D%281-r%5En%29%2F%281-r%29%5B%22%22%5D\"}\r\n" );
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document.write( "\"S%5B9%5D=18%281-0.6%5E9%29%2F%281-0.6%29\"\r\n" );
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document.write( "That works out with a calculator to be 44.54650368, then when we\r\n" );
document.write( "add the initial drop of 15 meters, we get\r\n" );
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document.write( "59.54650368 which rounds to 59.5 meters.\r\n" );
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document.write( "Edwin
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