Saved Bookmarks
| 1. |
In a video there are 3 characters A, B and C. A can build a building in 15 days and B can build the same in 30 days while C can destroy the building in 30 days. If, C works every day and A and B work every alternate day starting from A, what is the time required to build the building in the game?1. 59 days2. 29 days3. 39 days4. 49 days5. None of these |
|
Answer» Correct Answer - Option 1 : 59 days Given: A and B can build in 15 and 30 days respectively while C destroys the building in 30 days. A and B work in alternate days and C works every day. Formula used: Total work = resultant work per days × time in days Calculations: Let us assume, total work = LCM of (15, 30, 30) = 30 units Rate of work for A = 30/15 = 2 Rate of work for B = 30/30 = 1 Rate of work for C = 30/30 = 1 When, A & C work together, Rate of work = (2 - 1) = 1 work/day When B & C work together, Rate of work = (1 - 1) = 0 ∴ Positive work rate only for the days when A and C works together. ∴ No of working days required where A and C works together = 30/1 = 30 Now, as A and C worked 1st day. So, while they work 30 sessions, B and C will work (30 - 1) = 29 days. Total time required = 30 + 29 = 59 days |
|