# Time & Work – Section1

 Question #1: A completes a work in 12 days and B complete the same work in 24 days. If both of them work together, then the number of days required to complete the work will be: A) 7 days B) 8 days C) 9 days D) 10 days Option 'B' : 8 days Hint: If A can complete a work in x days and B can complete the same work in y days, then, both of them together can complete the work in x y/ x+ y days Therefore, here, the required number of days = 12 × 24/ 36 = 8 days. Question #2: If 3 persons can do 3 times of a particular work in 3 days, then, 7 persons can do 7 times of that work in : A) 3 days B) 4 days C) 5 days D) 6 days Option 'A' : 3 days Hint: That is, 1 person can do one time of the work in 3 days. Therefore, 7 persons can do 7 times work in the same 3 days itself. Question #3: 12 men work 8 hours per day to complete the work in 10 days. To complete the same work in 8 days, working 15 hours a day, the number of men required is : A) 7 days B) 8 days C) 9 days D) 6 days Option 'B' : 8 days Hint: That is, 1 work done = 12 × 8 × 10 Then, 12 8 × 10 = No. of men required × 15 × 8 No. of men required = 12 × 8 × 10/15× 10 = 8 days. Question #4: 30 laborers working 7 hours a day can finish a piece of work in 18 days. If the laborers work 6 hours a day, then the number of laborers required to finish the same piece of work in 30 days will be : A) 19 days B) 20 days C) 21 days D) 22 days Option 'C' : 21 days Hint: 1 work done = 30 × 7 ×18 = No. of laborers × 6 × 30 No. of laborers = 30 × 7 × 18/6 × 30 = 21 Question #5: A and B together can plough a field in 10 hours but by himself A requires 15 hours. How long would B take to plough the same field? A) 20 hours B) 30 hours C) 40 hours D) 50 hours Option 'B' : 30 hours Hint: If A and B together can do a piece of work in x days and A alone can do the same work in y days, then B alone can do the same work in x y/ y – x days. Therefore, the No. of hours required by B = 10 × 15/ 15 – 10 = 150/5 = 30 hours. Question #6: A can do a piece of work in 5 days and B can do the same work in 10 days. How many days will both take to complete the work? A) 1 1/3 days B) 4 1/3 days C) 2 1/3 days D) 3 1/3 days Option 'D' : 3 1/3 days Hint: If A can complete a work in x days and B can complete the same work in y days, then, both of them together can complete the work in x y/ x+ y days. That is, the required No. of days = 5 × 10/15 = 3 1/3 days. Question #7: A group of workers accepted to do a piece of work in 25 days. If 6 of them did not turn for the work and the remaining workers did the work in 40 days, then the original number of workers was : A) 14 B) 15 C) 16 D) 17 Option 'C' : 16 Hint: Let the original number of workers be ‘x’ Then, x × 25 = (x – 6) × 40 25x = 40x -240 240 = 40x -25x = 15x x = 240/15 = 16. Question #8: If 8 men can dig a well in 18 days, then the number of days, 12 men will take to dig the same well will be : A) 12 days B) 13 days C) 14 days D) 15 days Option 'A' : 12 days Hint: Work done = 8 × 18 Then, 8 × 18 = 12 × No. of days No. of days = 8 × 18/12 = 12 days Question #9: A certain number of men can do a work in 40days. If there were 8 men more, it could be finished in 10 days less. How many men were there initially? A) 23 B) 24 C) 25 D) 26 Option 'B' : 24 Hint: Let ‘x’ be the initial number of men Then, 1 work done = x × 40 Then, x × 40 = (x + 8) (40 – 10) 40x = 30x + 240 10x = 240 Therefore, x = 240/10 = 24 men. Question #10: A works twice as fast as B. if B can complete a work in 12 days independently. The number of days in which A and B can together finish the work? A) 5 days B) 6 days C) 4 days D) 3 days Option 'C' : 4 days Hint: If B takes 12 days to finish the work, then A takes 6 days to finish the same work. If A can complete a work in x days and B can complete the same work in y days, then, both of them together can complete the work in x y/ x+ y days. Therefore, the Number of days taken by A and B together to finish the same work = 6 × 12/18 = 4 days.