1996 AJHSME Problems/Problem 12
Adding all of the numbers gives us (11)(12/2)=66. Since there are 11 numbers, the average is 66/11=6. We need to take away a number from the total sum and then divide the result by 10 because there will only be 10 numbers left to give us 6.1. Setting up the equation, we get (66-x)/10=6.1. Solving for x gives 5 which is choice B.