The mean of 20 numbers is 43. If 6 is subtracted from each of the numbers, what will be the new mean?
Given,
Mean of 20 numbers = 43
Sum of these numbers = 20 × 43 = 860
When, every number is decreased by 6,
Total decrease in sum = 20 × 6 = 120
New sum will be = 860 – 120 = 740
New Mean = 
8