If the mean of numbers 28, x, 42, 78 and 104 is 62, what is the mean of 48, 62, 98, 124 and x?
If the mean of numbers 28, x, 42, 78 and 104 is 62, what is the mean of 48, 62, 98, 124 and x?
The correct option is B 78
x is common to both the series. So, x is not going to make a difference to the average. Only the remaining 4 numbers will contribute to the difference in average between the two series. Sum of the 4 numbers, excluding x, of the first series is 28 + 42 + 78 + 104 = 252, Sum of the 4 numbers, excluding x, of the second series is 48 + 62 + 98 + 124 = 332. The difference between the sum of the two sets of numbers = 332 - 252 = 80. The sum of the second series is 80 more than the sum of the first series. If the sum of the second series is 80 more, the average of the second series will be 805805 = 16 more than the first series. Therefore, the average of the second series = 62 + 16 = 78.
x is common to both the series. So, x is not going to make a difference to the average. Only the remaining 4 numbers will contribute to the difference in average between the two series. Sum of the 4 numbers, excluding x, of the first series is 28 + 42 + 78 + 104 = 252, Sum of the 4 numbers, excluding x, of the second series is 48 + 62 + 98 + 124 = 332. The difference between the sum of the two sets of numbers = 332 - 252 = 80. The sum of the second series is 80 more than the sum of the first series. If the sum of the second series is 80 more, the average of the second series will be 805805 = 16 more than the first series. Therefore, the average of the second series = 62 + 16 = 78.
