The average height of W, X, and Y is 185 cm. If the average height of W and X is 153 cm and the average height of X and Y is 152 cm, then what is the height of X?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 55 cm.
Average height of W, X, and Y = 185 cm
We know that,
Average = Sum of observations/Number of observations
The sum of the height of W, X, and Y = 3 × 185 = 555 cm
⇒ X + Y + Z = 555....(1)
Now,
The sum of the height of W and X = 2 × 153 = 306
⇒ W + X = 306....(2)
The sum of the height of X and Y = 152 × 2 = 304
⇒ X + Y = 304.....(3)
On putting eq (3) in eq (1)
⇒ 306 + Y = 555
⇒ Y = 555 - 306
⇒ Y = 249
Now,
⇒ X + 249 = 304
⇒ X = 304 - 249 = 55 cm
Thus, the height of X is 55 cm