Question 254957
If A can finish a job 50% faster than B and 20% faster than C, and together they can finish the job in 4 hours, how long would it take A to finish the job alone?
:
If A can finish a job 50% faster than B and 20% faster than C, and together they can finish the job in 4 hours, how long would it take A to finish the job alone?
:
let t = time required by A alone
then
1.5t = time required by B
and
1.2 = time required by C
:
Let the completed job = 1
:
{{{4/t}}} + {{{4/(1.5t)}}} + {{{4/(1.2t)}}} = 1
Multiply equation by 6t, results
6(4) + 4(4) + 5(4) = 6t
24 + 16 + 20 = 6t
60 = 6t
t = {{{60/6}}}
t = 10 hrs for A 
1.5(10) = 15 hrs for B
1.2(10) = 12 hrs for C
;
:
Check solution on a calc:
{{{4/10}}} + {{{4/15}}} + {{{4/12}}} = 1