37. A data set has 15 elements. The 15 elements in a second data set are obtained by multiplying each element in the first data set by 10. The 15 elements in a third data set are obtained by decreasing each element of the second data set by 20. The median of the third data set is 50. What is the median of the first data set?

Answer and Explanation

Your Answer is

Correct Answer is B

Explanation

The two operations do not change the size relationship of each item. So go back from the third set and get (50+20)÷10=7, so choose B.