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RRC Group D Previous Paper 19 (Held On: 10 Dec 2018 Shift 2)

Option 1 : 105, 210 and 70

A and B can complete a task in = 70 days

B and C can complete the task in = 52.5 days = 105/2 days

C and A can do the same task in = 42 days

Let altogether they can complete the task in x days

x (1/70 + 2/105 + 1/42) = 2

⇒ x [(3 + 4 + 5)/210] = 2

⇒ x (12/210) = 2

⇒ x = 2 × (210/12)

⇒ x = 35 days

A’s one day’s work = 1/35 - 2/105 = (3 - 2)/105 = 1/105

A alone can complete the whole task in = 105 days

B’s one day’s work = 1/35 - 1/42 = (6 - 5)/210 = 1/210

B alone can complete the whole task in = 210 days

C’s one day’s work = 1/35 - 1/70 = (2 - 1)/70 = 1/70

C alone can complete the whole task in = 70 daysRRC Group D Full Mock Test

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