A can do a piece of work in 30 days, B can do in 45 days and C can do ...
Given: A can do a piece of work in 30 days, B can do in 45 days and C can do the same work alone in 60 days.
Let the total work be 180 units (LCM of 30, 45 and 60).
On the first day, A alone does 6 units of work (180/30).
On the second day, A and B together do (6+4) 10 units of work (LCM of 30 and 45 is 90, and A does 3 units of work in 1 day while B does 2 units of work in 1 day. So, in 1 day they will do 5 units of work. So, in 2 days, they will do 10 units of work).
On the third day, A and C together do (6+3) 9 units of work (LCM of 30 and 60 is 60, and A does 1 unit of work in 1 day while C does 1/3 units of work in 1 day. So, in 1 day they will do 4/3 units of work. So, in 3 days, they will do 4 units of work).
So, in 3 days, they have done a total of 25 units of work (6+10+9).
To complete 180 units of work, they need 155 units more (180-25).
Let's calculate the next 3 days cycle:
On the fourth day, A alone does 6 units of work.
On the fifth day, A and B together do 10 units of work.
On the sixth day, A and C together do 9 units of work.
So, in 6 days, they have done a total of 50 units of work (25+6+10+9).
To complete 180 units of work, they need 130 units more (180-50).
Let's calculate the next 3 days cycle:
On the seventh day, A alone does 6 units of work.
On the eighth day, A and B together do 10 units of work.
On the ninth day, A and C together do 9 units of work.
So, in 9 days, they have done a total of 75 units of work (25+6+10+9+6+10+9).
To complete 180 units of work, they need 105 units more (180-75).
Let's calculate the next 3 days cycle:
On the tenth day, A alone does 6 units of work.
On the eleventh day, A and B together do 10 units of work.
On the twelfth day, A and C together do 9 units of work.
So, in 12 days, they have done a total of 100 units of work (25+6+10+9+6+10+9+6+10+9).
To complete 180 units of work, they need 80 units more (180-100).
Let's calculate the next 3 days cycle:
On the thirteenth day, A alone does 6 units of work.
On the fourteenth day, A and B together do 10 units of work.
On the fifteenth day, A and C together do 9 units of work.
So, in 15 days, they have done a total of 125