
Math General Math Forum  For general math related discussion and news 
 LinkBack  Thread Tools  Display Modes 
March 29th, 2017, 01:02 PM  #1 
Newbie Joined: Mar 2017 From: UK Posts: 3 Thanks: 1  Algebra conundrum
Alice is 5 years older than Bob. Let Bob be x. The product of their ages is 149 times the sum of their ages. Write an algebraic expression or equation and work out their ages. Any thoughts??? 
March 29th, 2017, 02:00 PM  #2 
Senior Member Joined: Sep 2015 From: CA Posts: 1,238 Thanks: 637 
Let Bob be $b$ $a = b+5$ $a b = 149(a+b)$ you can substitute the first equation into the second and solve for $b$ I leave that to you. 
March 29th, 2017, 02:29 PM  #3 
Global Moderator Joined: Dec 2006 Posts: 17,204 Thanks: 1291  
March 29th, 2017, 02:37 PM  #4 
Math Team Joined: Jul 2011 From: Texas Posts: 2,550 Thanks: 1260 
$x(x+5) = 149(2x+5)$ solution for $x$ is unreasonable, imho ... Is Bob's age in years? 
March 29th, 2017, 03:13 PM  #5 
Senior Member Joined: Sep 2015 From: CA Posts: 1,238 Thanks: 637  
March 29th, 2017, 11:58 PM  #6 
Newbie Joined: Mar 2017 From: UK Posts: 3 Thanks: 1 
It was a question in amongst some others on a piece of homework (not mine fortunately  belongs to a 13 year old!) and I was asked to help. I have still not been able to fathom out how to work out how old either Alice or Bob might be!! I went down the same route as you Skeeter but ended up with some ridiculous quadratic that made no sense in relation to ages ... 
March 30th, 2017, 06:18 PM  #7  
Math Team Joined: Oct 2011 From: Ottawa Ontario, Canada Posts: 9,446 Thanks: 640  Quote:
is if product of ages = 6 times the sum. Alice = 15, Bob = 10 or Alice = 2, Bob = 3 : Dad will release him 2 years 3 months from now!  

Tags 
algebra, conundrum 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Contract conundrum  jcd  Applied Math  1  July 23rd, 2015 07:45 AM 
reposted: sewing conundrum concerning cones  thewitchmaker  Topology  1  January 29th, 2015 07:06 AM 
sewing conundrum concerning cones  thewitchmaker  Geometry  1  January 28th, 2015 05:19 PM 
Probability conundrum  floodric  Probability and Statistics  4  February 24th, 2014 11:01 AM 
A conundrum....  random_thinker  Applied Math  2  June 25th, 2009 04:41 AM 