Sam can do a job in 4 days that Lisa can do in 6 days and Tom can do in 2 days, how long would the job take if Sam, Lisa, and Tom worked together to complete it?

A. 0.8 days
B. 1.09 days
C. 1.23 days
D. 1.65 days
E. 1.97 days
thanks.

First add the "jobs per day" rates of all three people.

1/4 + 1/6 + 1/2 = (3 + 2 + 6)/12 = 11/12 jobs per day
Then divide 1 job by 11/12 jobs/day to get the answer: 12/11 = 1.09 days

To find the time it would take for Sam, Lisa, and Tom to complete the job together, you can use the concept of "work rates."

First, find the work rates for each person. Sam can do the job in 4 days, so his work rate is 1 job per 4 days (1/4). Lisa can do the job in 6 days, so her work rate is 1 job per 6 days (1/6). Tom can do the job in 2 days, so his work rate is 1 job per 2 days (1/2).

To find the combined work rate of Sam, Lisa, and Tom, you add up their individual work rates:
1/4 + 1/6 + 1/2 = 3/12 + 2/12 + 6/12 = 11/12

This means that together, they can complete 11/12 of the job in one day. To find how long it would take to complete the entire job, you divide 1 by the combined work rate:
1 / (11/12) = 12/11 ≈ 1.09

Therefore, the answer is B. 1.09 days.