Question

Here are five number cards. 1 4 6 8 9. One of the cards is removed and the mean average of the remaining four number cards is 6. Which card was removed?

Answer 1

The number 4 was removed.

Explanation:

I went through and removed one number at a time, adding up all of the other numbers (equaling 24) then dividing them by 4 (the amount of numbers left) to get 6.