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cmh09
Apr 25, 2010, 08:02 PM
Im am challenged when it comes to word problems, please help!
Sammy takes 5 hours longer to complete 300 lines of code than Martin. Together, Sammy and Martin can complete the code in 6 hours.
Clearly explain the results showing the calculations of how long it takes each programmer to complete the code if he programs on his own and at what speed he is programming lines per hour.

i know it needs to be a quadratic equation but im lost

Unknown008
Apr 26, 2010, 08:48 AM
Let the time that Sammy takes be 't' to complete 300 lines of code.
Then, Martin must be doing 300 lines of codes in 5 hours less, or 't-5'

If they work together, they should take less time than if they work separately, right? So, this means that you need to use the format:

\frac{1}{t_1} + \frac{1}{t_2} = \frac{1}{t_{total}}

Let t1 be the time taken by Sammy, t2 that taken by Martin.
Sub in the values, to give:

\frac{1}{t} + \frac{1}{t-5} = \frac{1}{6}

Now it should be easier from here :)

Post your answer!

lloyd_a3
Sep 22, 2010, 02:07 PM
1/t+1/t-5=1/6
get the lcd
the lcd is (t)(t-5)(6)
multiply it into the equation
t(t-5)(6)[(1/t+1/t-5+1/6)]
t-5(6t)+t(6)=t-5(t)
6t^2-5+6t=T^2-5
6t^2-t^2+6t+5-5=0
5t^2+6t=0
use the quadratic equation to continue it
=lloyd_a3