Pipes A and B running together can fill a cistern in 6min. If B takes 5 min more than A to fill the cistern, then the times in which A and B will fill the cistern separately will be respectively
Answer: C Let pipe A fills the cistern in x minutes. Therefore, pipe B will fill the cistern in (x+5) min. 1/x + 1/(x+5) = 1/6 => x=10. Hence pipe A and B can fill the cistern in 10 and 15 minutes.
Q. No. 8:
Two men and 7 children complete a certain piece of work in 4 days while 4 men and 4 children complete the same work in only 3 days. The number of days required by 1 man to complete the work is
Answer: C (2M+7C)'s 1 day work = 1/4 It means that 1 work will be finished by (8M+28C) Again (4M+4C)'s 1 day work = 1/3 or 1 work will be completed by 12M+12C Therefore, 8M+28C = 12M+12C => M=4C => 4M+4C = 5M Since, 5 men complete a work in 3 days. Then 1 man will complete it in 15 days.
Q. No. 9:
Mr. Ram is on tour and he has Rs 360 for his expenses. If he exceeds his tour by 4 days he must cut down daily expenses by Rs 3. The number of days of Mr. Ram's tour programme is
Answer: A Let Ram under takes a tour of x days. Then, expenses for each day = 360/x. => 360/(x+4) = 360/x - 3 => x= 20 and -24 Hence , x= 20 days.
Q. No. 10:
A tap can fill a tank in 16 min and another can empty it in 8 min. If the tank is already 1/2 full and both the taps are opened together, will the tank be filled or emptied? How long will it take before the tank is either filled or emptied completely as the case may be?
Answer: C If both the pumps are working together then the tank will be emptied because the work efficiency of pump empting is more than that of pump filling it. Hence, in 1 min net work done = (1/8 - 1/16) = 1/16 tanks. or 1 tank will be emptied in 16 min. or 1/2 tank will be emptied in 8 min.
Q. No. 11:
A contractor undertakes to build a wall in 50 days. He employs 50 people for the same. However after 25 days he finds that only 40% of the work is complete. How many more man need to be employed to complete the work in time?
Answer: D It is given that 50 men completes 0.4 work in 25 days. m1*d1*w2 = m2*d2*w1 50*25*0.6 = m2*25*0.4 m2 = 75 men. Number of additional men required = 75 -50 = 25 men
Q. No. 12:
A can do a piece of work in 10 days, while B alone can do it in 15days. They work together for 5 days and the rest of the work is done by C in 2 days. If they get Rs 450 for the whole work, how should they divide the money?
Answer: A Work done by A and B in 5 days = (1/10 + 1/15)*5 = 5/6 Remaining work = 1/6. C alone can do the work in 6*2 = 12 days. Ratio of work = 5/10 : 5/15 : 2/12 => 3:2:1 Thus , the total amount of money =6x (say) => 6x = 450 => x= 75. Thus money they got is 3x, 2x and x respectively.