JEE Main 2019 Mathematics question
The mean and the variance of five observations are 4 and 5.20, respectively. If three of the observations are 3, 4 and 4; then the absolute value of the difference of the other two observations, is:
Answer: (B)
Solution
a + b = 9, ⇒ ab = 8 ⇒ |a − b| = √(81 − 32) = 7.