The average of P, Q, and R is 40. If the average of P and Q is 35 and the average of Q and R is 45, what is the value of Q?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 40.
We know that,
Average = Sum of observations/Number of observations
Now,
The average of P, Q, and R is 40
Sum of P, Q and R = 3 × 40 = 120
The average of P and Q is 35
Sum of P and Q = 35 × 2 = 70
The average of Q and R is 45
Sum of Q and R = 2 × 45 = 90
Now,
The value of R = (P + Q + R) - (P + Q) = 120 - 70
The value of R = 50
Now,
The value of Q = (Q + R) - R
⇒ 90 - 50 = 40