a person a can do a piece of work in 9 days, whereas another person b can do the same piece of work in 12 days. because of busy schedule, they decide to work one day alternately. if b is the first one to start, find the time required for the work to be completed. consider that if a part of day is used, the whole day is to be counted.
Answers
Percentage Method:
A can complete work in 9 days.
So, percentage of work A compltes in one day = 100/9 = 11.11%.
B can complete work in 12 days.
B's one day work = 100/12 = 8.33%.
A and B together can complete = 11.11 +8.33 = 19.44% of work in one day.
Now,
Take 2 days = 1 unit of time (one day of A and one of B).
In one unit of time A and B can complete work = 19.44% work.
Total time unit they need to complete whole work = 100/(19.44) = 5 time unit aprox.
Thus, Total time = 5 time unit = 5 *2 = 10 days.
Fraction Method:
A can complete total work in 9 days.
One day work of A = 1/9 part.
B can complete work in 12 days.
One day work of B = 1/12 part.
A and B together can complete work in one day,
= 1/9 + 1/12
= (4 +3)/36 = 7/36 part.
Take, 2 days = 1 time unit.
To time unit needed to complete the work,
= 1/(7/36) = 36/7 = 5 time unit approx.
Total Time = 2 *5 = 10 days.
A can complete work in 9 days.
So, percentage of work A compltes in one day = 100/9 = 11.11%.
B can complete work in 12 days.
B's one day work = 100/12 = 8.33%.
A and B together can complete = 11.11 +8.33 = 19.44% of work in one day.
Now,
Take 2 days = 1 unit of time (one day of A and one of B).
In one unit of time A and B can complete work = 19.44% work.
Total time unit they need to complete whole work = 100/(19.44) = 5 time unit aprox.
Thus, Total time = 5 time unit = 5 *2 = 10 days.
Fraction Method:
A can complete total work in 9 days.
One day work of A = 1/9 part.
B can complete work in 12 days.
One day work of B = 1/12 part.
A and B together can complete work in one day,
= 1/9 + 1/12
= (4 +3)/36 = 7/36 part.
Take, 2 days = 1 time unit.
To time unit needed to complete the work,
= 1/(7/36) = 36/7 = 5 time unit approx.
Total Time = 2 *5 = 10 days.