Suppose the mean of 30 numbers is 520. If 20 of these numbers are each increased by 12, and remaining numbers are decreased by 6, then the mean of the new set of numbers is:
A) 4860
B) 5060
C) 5260
D) 5460
E) None of these.
A) 4860
B) 5060
C) 5260
D) 5460
E) None of these.