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6. Two workers A and B are engaged to do a work. A working alone takes 8 hours more to complete the job than if both worked together. If B worked alone, he would need 4 1/2 hours more to complete the job than they both working together. what time would they take to do the work together?

AnswerAnswer: OptionA Explanation:

Let A and B together take x hours to complete the work. then, A alone takes (x+8) hrs and B alone takes (x + 9/2) hrs to complete the work. then, 1/(x+8) + 1/(x+9/2) = 1/x = 1(x+8)+ 2/(2x + 9) = 1/x = x(4x + 25) = (x+8) (2x+9) = 2x^2 = 72 = x^2 =36 = x =6.

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7. Ronald and elan are working on assignment. Ronald takes 6 hours to type 32 pages on a computer, while elan takes 5 hours to type 40 pages. how much time will they take, working together on two different computers to type an assignment of 110 pages?

AnswerAnswer: OptionC Explanation:

Number of pages typed by Ronald in 1 hour = 32/6 = 16/3. Number of pages typed by elan in 1 hour = 40/5 = 8. Number of pages typed by both in 1 hour = (16/3 + 8) = 40/3. therefore time taken by both to type 110 pages = (110*3/40) hrs = 8 hrs 15 min.

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8. P,Q and R three typists who working simultaneously can type 216 pages in 4 hours.In one hour R can type as many pages more than Q as Q can type more than P.During a period of 5 hours R can type many pages as P can during 7 hours. How many pages does each of them type per hour?

AnswerAnswer: OptionC Explanation:

Let the number of pages typed in one hour by P,Q, and R be x,y, and z respectively. x+y+z = 216/4 = x+y+z = 54 .........(1) z-y = y-x = 2y = x+z .........(2) 5z = 7x = x = 5/7z .........(3) solving (1) (2) and (3) we get x = 15; y= 18 ; z = 21

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9. P can complete a work in 12 days working 8 hours a day. Q can complete the same work in 8 days working 10 hours a day. If both P and Q work together, working 8 hours a day, in how many days can they complete the work?

AnswerAnswer: OptionC Explanation:

P can complete the work in (12*8) hrs. = 96 hrs. Q can complete the work in (8*10) hrs. = 80 hrs. therefore P's 1 hour's work = 1/96 and Q' s 1 hour's work = 1/80. (P + Q)'s 1 hour' s work = ( 1/96 + 1/80) = 11/480. so both P and Q will finish the work in (480/ 11) hrs. therefore number of days of 8 hours each = (480/11*1/8) = 60/11 days = 5 5/11 days.

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10. A,B and C can complete a piece of work in 24,6 and 12 days respectively. Working together, they will complete the same work in