Four numbers have a mean of 6. Two numbers are added and the mean increases by 1. One of the numbers is twice the other. What were the numbers?
total of the 4 numbers is 24
new numbers added, x and 2x
new sum = 24 + 3x
(24+3x)/6 = 5
24 + 3x = 30
3x = 6
x = 2
the numbers added were 2 and 4