Question

Mental Arithmetic: work the following exercises in your head. Do not calculate with a pencil or paper. Do not use a

decimal.
Think of the number seven.
Now add eight to it.
Now add four more.
Now subtract nine.
Now add three.
Your answer is
14
13
12
11

Answer 1

7 + 8
15 + 4
19 - 9
10 + 3
13
I know it said not to work it out on paper but here’s how to get the answer.

Answer 2

The answer is the second option (13)