Average (Railway Maths) (Part – III)

Total Questions: 35

31. The mean score in a test of the 12 boys in a class was 16 while the overall mean score of the 30 students in the class was 18.1. What was the mean score of the girls? [RRB ALP 20/08/2018 (Morning)]

Correct Answer: (c) 19.5
Solution:

32. Mean temperature of a city for a week is 28°C. If the mean temperature for Monday, Tuesday, Wednesday and Thursday is 27.5°C and the mean temperature for Thursday, Friday, Saturday and Sunday is 29°C, the temperature recorded for Thursday is. [RRB ALP 29/08/2018 (Evening)]

Correct Answer: (a) 30°C
Solution:

33. In a class when a test is conducted, mean of 25 students marks is 60. If mean of first 13 students marks is 70 and mean of last 13 students marks is 50, find the marks of the middle student when arranged in the ascending order. [RRB ALP 30/08/2018 (Morning)]

Correct Answer: (c) 60
Solution:

34. The mean of the 5 smallest numbers from a group is 15 while the mean of all the 13 numbers of the group taken together is 17. What is the mean of the 8 largest numbers? [RRB ALP 30/08/2018 (Morning)]

Correct Answer: (b) 18.25
Solution:

35. The average marks obtained by a group of 16 students was 20. One student left the group as a result of which the average of the remaining students rose to 21. But another student joined, as a result of which the average marks of the group dropped a bit and became 20.5. What was the average marks obtained by the student who left and the one who joined? [RRB ALP 31/08/2018 (Evening)]

Correct Answer: (a) 9
Solution: