Question

A take 6 day less time than B to finish a pieace of work if A and B work together and finish in 4 day then find time taken by A
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Answer 1

Step-by-step explanation:

Suppose B alone takes x days to finish the work. Then A alone can finish it in (x−6) days

Now A's one day's work + B's one day's work =

x

1

+

x−6

1

and (A+B)'s one day's work =

4

1

∴

x

1

+

x−6

1

=

4

1

⇒

x(x−6)

x−6+x

=

4

1

⇒

x

2

−6x

2x−6

=

4

1

⇒8x−24=x

2

−6x

⇒x

2

−14x+24=0

⇒x

2

−12x−2x+24=0

⇒(x−12)(x−2)=0

⇒x=12orx=2

But x cannot be less than 6.

So x=12

Hence, B also can finish the work in 12 days.