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: 407  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:
 

Tags 
ratios 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Trigonometric Ratios  bilano99  Trigonometry  2  November 12th, 2012 10:56 AM 
Ratios  linhbui  Elementary Math  4  August 22nd, 2012 06:24 AM 
Help with Trignometric Ratios  jattrockz  Trigonometry  5  November 10th, 2011 12:17 PM 
Ratios/fractions  MathematicallyObtuse  Algebra  4  January 1st, 2011 05:04 PM 
ratios and fractions  arun  Number Theory  6  February 21st, 2007 05:32 PM 