Question

a takes 10 days less than the time taken by b to finish a piece of work if both A and B together can finish a piece of work in 12 days find the time taken by b alone​

Answer 1

Answer:

9

Step-by-step explanation:

Answer 2

Solution:

let B takes time = x days

& A takes time = y days

→time taken by together A & B = 12

=> x.y/(x+y) = 12 --- (1).

according to question,

y=x-10

put y in (1),

=> x(x-10)/[x+(x-10)] = 12

=> (x^2-10x)/(2x-10) = 12

=> x^2 -10x = 24x-120

=> x^2-34x+120 = 0

=> x^2-30x-4x+120=0

=> (x-4)(x-30) = 0

=> x=4 & x=30

here x can't be equal to 4.

( as,time taken by A will be,

=> 4-10=-6, which is not possible)

=> x= 30

Hence A complete the work in 20 days and B in 20+10 = 30 days