Q: A, B and C together can finish a task in 12 days. A is twice as productive as B and C alone can do the task in 36 days. In how many days can A and B do the task if C goes on leave?
Solution: 18
Q: 12 men complete a work in 14 days. 5 days after they had started working, 3 men join them. How many more days will all of them take to complete the remaining work?
Solution: Let p be the required number of days. From the given data, 12 x 14 = 12 x 5 + (12+3) x p 12 x 14 = 12[5 + 3p] 14 = 5 + 3p 3p = 9 p = 3 days. Hence, more 3 days all of them take to complete the remaining work
Q: A can do 1/2 of a piece of work in 8 days while B can do1/3of the same work in 8 days. In how many days can both do it together?
Solution: A completed their work in 8 X 2 = 16 days B completed their work in 8 X 3 = 24 days A and B one day work1/16 + 1/245/48 A and B completed their work in 48/5 days = 9.6 days
Q: Three athletes can complete one round around a circular field in 16, 24 and 36 min respectively. They start running together at same instant then after how much time they will meet to each other for first time ?
Solution: Given that three athletes can complete one round around a circular field in 16, 24 and 36 min respectively. Now, required time after which they met for the first time = LCM of (16, 24 & 36) min Now, LCM of 16, 24, 36 = 144 minutes = 2 hrs 24 min.
Q: If m and n are whole numbers such that mn = 121, the value of (m - 1)n + 1 is:
Solution: We know that 112 = 121. Putting m = 11 and n = 2, we get: (m - 1)n + 1 = (11 - 1)(2 + 1) = 103 = 1000.
Q: Two pipes A and B can fill a cistern in 20 and 30 minutes respectively, and a third pipe C can empty it in 40 minutes. How long will it take to fill the cistern if all the three are opened at the same time?
Solution: 1/20 + 1/30 - 1/40 = 7/120 120/7 = 17 1/7
Q: Two pipes A and B can separately fill a tank in 2 minutes and 15 minutes respectively. Both the pipes are opened together but 4 minutes after the start the pipe A is turned off. How much time will it take to fill the tank?
Solution: 4/12 + x/15 = 1 x = 10
Q: A cistern has a leak which would empty the cistern in 20 minutes. A tap is turned on which admits 4 liters a minute into the cistern, and it is emptied in 24 minutes. How many liters does the cistern hold?
Solution: 1/x - 1/20 = -1/24 x = 120 120 * 4 = 480
Q: Two pipes A and B can fill a tank in 4 and 5 hours respectively. If they are turned up alternately for one hour each, the time taken to fill the tank is?
Solution: 1/4 + 1/5 = 9/20 20/9 = 2 2/9 9/20 * 2 = 9/10 ---- 4 hours WR = 1 - 9/10 = 1/10 1 h ---- 1/4 ? ----- 1/10 2/5 * 60 = 24 = 4 hrs 24 min
Q: Two pipes A and B can separately fill a tank in 12 and 15 minutes respectively. A third pipe C can drain off 45 liters of water per minute. If all the pipes are opened, the tank can be filled in 15 minutes. What is the capacity of the tank?
Solution: 1/12 + 1/15 - 1/x = 1/15 x = 12 12 * 45 = 540
| You Have Score | /10 |