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Work from Days:

1.	A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is :
	A. 1 4 B. 1 10 C. 7 15 D. 8 15 Answer & Explanation Answer: Option D Explanation: A's 1 day's work = 1 ; 15 B's 1 day's work = 1 ; 20 (A + B)'s 1 day's work = 1 + 1 = 7 . 15 20 60 (A + B)'s 4 day's work = 7 x 4 = 7 . 60 15 Therefore, Remaining work = 1 - 7 = 8 . 15 15

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2.	A can lay railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days only. Then, C alone can do the job in:
	A. 9 1 days 5 B. 9 2 days 5 C. 9 3 days 5 D. 10 Answer & Explanation Answer: Option C Explanation: (A + B + C)'s 1 day's work = 1 , 4 A's 1 day's work = 1 , 16 B's 1 day's work = 1 . 12 C's 1 day's work = 1 - 1 + 1 = 1 - 7 = 5 . 4 16 12 4 48 48 So, C alone can do the work in 48 = 9 3 days. 5 5

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3.	A, B and C can do a piece of work in 20, 30 and 60 days respectively. In how many days can A do the work if he is assisted by B and C on every third day?
	A. 12 days B. 15 days C. 16 days D. 18 days Answer & Explanation Answer: Option B Explanation: A's 2 day's work = 1 x 2 = 1 . 20 10 (A + B + C)'s 1 day's work = 1 + 1 + 1 = 6 = 1 . 20 30 60 60 10 Work done in 3 days = 1 + 1 = 1 . 10 10 5 Now, 1 work is done in 3 days. 5 Whole work will be done in (3 x 5) = 15 days.

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4.	A alone can do a piece of work in 6 days and B alone in 8 days. A and B undertook to do it for Rs. 3200. With the help of C, they completed the work in 3 days. How much is to be paid to C?
	A. Rs. 375 B. Rs. 400 C. Rs. 600 D. Rs. 800 Answer & Explanation Answer: Option B Explanation: C's 1 day's work = 1 - 1 + 1 = 1 - 7 = 1 . 3 6 8 3 24 24 A's wages : B's wages : C's wages = 1 : 1 : 1 = 4 : 3 : 1. 6 8 24 C's share (for 3 days) = Rs. 3 x 1 x 3200 = Rs. 400. 24