निम्नलिखित अवर्गीकृत आंकड़ों का माध्य क्या है? प्राप्तांक: 3, 2, 1, 4, 5

The arithmetic mean of a series of 8 numbers is 25. If six of the numbers are 2, 12, 22, 32, 42, and 52, what is the sum of the remaining 2 numbers, and which pair among the options gives that sum?

There are four numbers in a set. The mean of the three smallest numbers is 9, whereas the mean of the three largest ones is 11. What is the range of the data set?