Question

Here are five number cards

2,5,7,8,9

one of the cards is removed and the mean average of the remaining four number cards is 6

which card was removed
show your working

Answer 1

7

Explanation:

Since one card was removed:

6 = x/4

x = 6 X 4

x = 24

Then you sum the numbers on the five cards and subtract 24 from it

(2 + 5 + 7 + 8 + 9) - 24

= 31 - 24

= 7

Therefore card with number 7 was removed.