The average of x, y and z is 30, and the average of x and y is 20. What is the value of z?
10
20
40
50
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC CAPF – 2012
Given: Average of x, y, and z is 30.
This means (x + y + z) / 3 = 30.
Multiplying both sides by 3, we get: x + y + z = 30 * 3 = 90. (Equation 1)
Given: Average of x and y is 20.
This means (x + y) / 2 = 20.
Multiplying both sides by 2, we get: x + y = 20 * 2 = 40. (Equation 2)
Now substitute the value of (x + y) from Equation 2 into Equation 1:
40 + z = 90.
To find z, subtract 40 from both sides:
z = 90 – 40
z = 50.