JEE Main 202118 Mar, Evening shiftMathematicsMediumStatistics and Probability258× since 2002
Let in a series of 2n observations, half of them are equal to a and remaining half are equal to a. Also by adding a constant b in each of these observations, the mean and standard deviation of new set become 5 and 20, respectively. Then the value of a² + b² is equal to :