A, B and C can do a piece of work in 20, 30 and 100 days respectively. If A worked alone on the first day, B worked alone on the second day, C worked alone on the third day, A worked alone on the fourth day, and so on, then in how many days the work got completed?
1) 29 days
2) 28 days
3) 31 1/2 days
4) Can't be determined

• A's, B's and C's 1 day work = 1/20 + 1/30 + 1/100
  
  Total 3 day's work = 28/300
  Total 30 day work = 280/300
  Remaining work = 20/300 = 1/15
  Now A's 1 day work = 1/20
  Then remaining work = (1/60)/(1/30) = 1/2
  Now, B's then B complet the remaining work in 1/2
  Total number of days = 31 1/2 days.
  
• 8 years agoHelpfull: Yes(4) No(6)
• take lcm of 20,30,100 it is 600. a can complete 30 works in a day,b can complete 20 works in a day, c can complete 6 works in a day,togeather abc can complete 56 works per day..in 30 days abc completes 560 works on so remaining 40 works left on 31 day a complete 30 works remaining we have 10 works c completes in hald day so ans is 31 1/2.
• 7 years agoHelpfull: Yes(1) No(2)