Bihar Police Constable Model Paper 7

Given:
Average of the five numbers = -5
Sum of the first three numbers = 15
Formula Used:
Average of observations = Sum of all the numbers in the observations/Number of observations
Calculation:
Let the five numbers be a, b, c, d, and e.
So, we have:
a + b + c + d + e = 5 × -5 = -25 ----(i)
Also, a + b + c = 15 ----(ii)
On substituting the value of equation (i) into equation (ii), we get:
15 + d + e = -25
⇒ d + e = -40
⇒ Average of d and e = -40/2 = -20
∴ The average of the last two numbers is -20