Question 396307
This type of problem is about adding
the rates at which people work to get
the final rate at which the job is finished
You want an equation that looks like:
(fraction of job)/(time to do it) + (different fraction of job)/(time to do it)
= (1 whole job)/(time to do the whole job)
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You start out with 2 people working. What part of the job
does each one do in 8 days?
Each one can do 1/2 of the job in 8 days
Every additional person can be expected to do (1 job)/(16 days)
So far I've got:
{{{(1/2)/8 + (1/2)/8 + x*(1/16) = 1/6}}}
Note that {{{x}}} represents the number of extra persons to hire
{{{(1/2)/8 + (1/2)/8 + x*(1/16) = 1/6}}}
Multiply both sides by {{{16}}}
{{{1 + 1 + x = 16/6}}}
Multiply bopth sides by {{{6}}}
{{{6 + 6 + 6x = 16}}}
{{{6x = 4}}}
{{{x = 2/3}}}
You can't hire 2/3 of a person. so 1 extra person must be hired
Hope I got it