Answer:
16 days.
Step-by-step explanation:
The work done by a and b in one day = 1/30
The work done by b and c in one day = 1/24
The work done by c and a in one day = 1/20
Find the sum of all these fractions , this will be the work done by 2a and 2b and 2c in one day. This gives 0.125, which is equivalent to 1/8.
The work done by 2 of each person = 8, so it takes double this value for just one of each person, this is 16 days.
Hope this helps
