January 9th, 2011, 06:54 AM  #1 
Senior Member Joined: Oct 2010 Posts: 126 Thanks: 0  Ratios
How do I solve this? In an election for senior class president, Alice received 30 votes more than David. If the ratio of the number of votes Alice received to the number of votes David received was 8 to 7, how many votes did David receive? I have two unknowns: # of votes David receives = 7/15 times some number to give 30 + some number. 
January 9th, 2011, 07:27 AM  #2 
Newbie Joined: Jan 2011 Posts: 22 Thanks: 0  Re: Ratios
If the ratio is 8:7 doesn't it just mean that David received 7*30 votes, which is 210? Or am I missing something silly Or using simultaneous equations: a  30 = d 7/8a = d 8a  240 = 8d 7a = 8d a  240 = 0 a = 240 d = 210 
January 9th, 2011, 07:45 AM  #3  
Math Team Joined: Dec 2006 From: Lexington, MA Posts: 3,267 Thanks: 408  Re: Ratios Hello, Chimoo! Quote:
Absolutely correct! A terrific "eyeball" solution!  
January 9th, 2011, 08:07 AM  #4  
Senior Member Joined: Oct 2010 Posts: 126 Thanks: 0  Re: Ratios Quote:
 

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