Madhya Pradesh Police Exam Model Paper 6

Given:
Average of 11 numbers = 28
Average of first 5 numbers = 23
Average of next 5 numbers = 25
Formula used:
Sum of observations = Average × Number of observations
Calculation:
Sum of 11 numbers =28×11
⇒ 308
Sum of first 5 numbers =23×5
⇒ 115
Sum of next 5 numbers =25×5
⇒ 125
Total sum of first 10 numbers =(115+125)
⇒ 240
11th number =(308–240)
⇒ 68
∴ The 11th number is 68