Question

14.

Answer 1

Answer:

10 days

Step-by-step explanation:

Mogaka and Ondiso working together can do a piece of job in 6 days. Mogaka working alone takes 5 days longer than Ondiso. How many days does it take Ondiso to do the work alone?

Let us represent :

The number of days

Mogaka worked alone = x

Ondiso worked alone = y

Total days worked together = T

Mogaka and Ondiso working together can do a piece of job in 6 days.

Hence,

1/x + 1/y = 1/T

Mogaka working alone takes 5 days longer than Ondiso.

x = y + 5

Therefore:

1/y + 5 + 1/y = 1/6

Multiply all through by (y+5)(y)

= y + y + 5 = (y+5)(y)/6

= 2y + 5/1 = (y+5)(y)/6

Cross Multiply

6( 2y + 5) = (y+5)(y)

12y + 30 = y² + 5y

= y² + 5y - 12y - 30 = 0

= y² - 7y - 30 = 0

Factorise

= y² +3y - 10y - 30 = 0

y(y + 3) - 10(y + 3) = 0

(y + 3)(y -10)= 0

y + 3 = 0, y = -3

y - 10 = 0

y = 10 days

Note that

The number of days Ondiso worked alone = y

Hence, it takes 10 days for Ondiso to work alone