Time taken by A to complete a work is 7 days
more than the time taken by B to complete the
same work. Working together they can complete
the work in 12 days. In what time can A alone
complete the work?
Answer in detail plzz
Answers
Answered by
2
Answer:
28 days
Step-by-step explanation:
let B take x days to complete the work
A takes x+7 days to complete the work
they together take 12 days
in 1 day B works 1/x
and A works 1/(x+7)
1/x+1/(x+7)=1/12
2x+7/x^2+7x=1/12
24x+84=x^2+7x
x^2-17x-84=0
x^2-21x+4x-84=0
x(x-21)+4(x-21)=0
(x-21)(x+4)=0
x=21
A takes x+7 days=28 days
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