A person cando a job in 6 days. Another cando the same job in 4 days. If they work together,

how long do they need to finish the job?

2.4 days

Step-by-step explanation:

(Not sure if this is correct)

I let the first worker productivity, p (The amount of work a person can do in one day) = 1, so I know:

6 * (1) = 6

6 will be the quantitative measure of work amount need to complete.

The second worker takes 4 days to complete:

4 * (p for second worker) = 6

Why equal to 6?

- Because they do the same amount of work.

From here I can know the productivity of second worker is 3 / 2.

The combined productivity of 2 workers will be 5 / 2

(Days needed) * 5/2 = 6

Days needed = 2.4

2.5 days