21. A cow is tethered in the middle of a field with a 14 feet long rope. If the cow grazes 100 sq. ft. per day, then approximately what time will be taken by the cow to graze the whole field ?
1. 2 days
2. 6 days
3. 18 days
4. 24 days
5. None of these
22. 2 hours after a freight train leaves Delhi a passenger train leaves the same station travelling in the same direction at an average speed of 16 km/hr. After travelling 4 hrs the passenger train overtakes the freight train. The average speed of the freight train was?
1. 40
2. 30
3. 80
4. 60

23. 2 numbers differ by 5.If their product is 336,then the sum of the 2 numbers is:
1. 21
2. 51
3. 28
4. 37

24. A radio when sold at a certain price gives a gain of 20%. What will be the gain percent, if sold for thrice the price?
1. 280
2. 270
3. 290
4. 260

25. x% of y is y% of ?
1. x/y
2. 2y
3. x
4. cant be determined

26. If the value of x lies between 0 & 1 which of the following is the largest?
1. x
2. x2
3. -x
4. 1/x

27. Thirty men take 20 days to complete a job working 9 hours a day. How many hour a day should 40 men work to complete the job?
1. 8 hrs
2. 71/2 hrs
3. 7 hrs
4. 9 hrs

28. A and B can do a piece of work in 45 days and 40 days respectively. They began to do the work together but A leaves after some days and then B completed the remaining work n 23 days. The number of days after which A left the work was
1. 9
2. 11
3. 12
4. 15
5. 16

29. On sports day, if 30 children were made to stand in a column, 16 columns could be formed. If 24 children were made to stand in a column, how many columns could be formed?
1. 20
2. 30
3. 40
4. 50

30. The probability that a man will be alive for 25 years is 3/5 and the probability that his wife will be alive for 25 years is 2/3. Find the probability that only the man will be alive for 25 years.
1. 2/5
2. 1/5
3. 3/5
4. 4/5