Question

,
A take 10 more days than B to finish a work
Ag B finish the work in 12 days together.
Find the time taken by B to complete the
wore ad alone​

Answer 1

Answer:

Correct option is

B

30 days

Let B alone finish the work =xdays.

And Alone finish the work =(x−10)days

A' s one day work =

x−10

1

B's one day work =

x

1

As it given tha

(A+B) can finish work in 12 days

∴(A+B)onedaywork=

12

1

⇒A

′

sonedaywork+B

′

sonedaywork=

12

1

⇒

x−10

1

+

x

1

=

12

1

⇒

x(x−10)

x+x−10

=

12

1

⇒

x(x−10)

2x−10

=

12

1

⇒12(2x−10)=x(x−10)

⇒24x−120=x

2

−10x

⇒x

2

−10x−24x+120=0

⇒x

2

−34x+120=0

⇒x

2

−30x−4x+120=0

⇒x(x−30)−4(x−30)=0

⇒(x−4)(x−30)=0

⇒x=4orx=30

x



=4

∵ifx=4thenAalonecanfinishtheworkin=(4−10)=−6dayswhichisnotpossible

∴x=30days

B alone can finish work in 30 days