Question 940286
two roads crew working together repaired 1 mile of the road in four hours.
 working separately one of the crews takes about six hours to repair a similar road.
 how long would it take the other crew working alone to repair a similar Road?
:
let t = time required by the "other crew" to do the job
let the completed job = 1
:
{{{4/6}}} + {{{4/t}}} = 1
Each crew does a fraction of the job, the two fractions add up to 1
multiply equation by 6t, cancel the denominators and you have:
4t + 6(4) = 6t
24 = 6t - 4t
24 = 2t
t = 24/2
t = 12 hrs for the other crew to do the job
:
;
Check this
{{{4/6}}} + {{{4/12}}} = 1
reduce fractions
{{{2/3}}} + {{{1/3}}} = 1