Averages

Q.48: If M is a positive integer such that average of 31, 33, M, 36. 37 lies b/w 40 and 43 (both inclusive). What is the number of possible values of M?

1. 16
2. 20
3. 24
4. No such M exists

 

Detailed Solution

31+33+36+37 = 137
If Avg (inc M) = 40 = ) Total 40 x 5 = 200 = ) M = 200 – 137 = 63
If Avg (inc M) = 43 = ) Total 43 x 5 = 215 = ) M = 215 – 137 = 78
Therefore, Number of possible values M can take = 78 – 63 + 1 (Don’t forget to add the 1) = 16







Correct Answer: 16