Question

Mike thought of a number. He added to it two other numbers. One of these numbers was 12 less than his number, the other was 12 more than his number. The result of addition was 15. What was Mike’s original number?

Answer 1

Let us say the number was x.

Mike added to it two other numbers.

First number added is 12 less than the original number.

So first number is x-12.

Second number added is 12 more than the original number.

So second number is x+12.

Now we are given that the result of adding all three numbers is 15.

Converting the information given into equation, we have:

original number + first number + second number =15

$x+(x-12)+(x+12)=15$

Adding like terms,

$3x=15$

dividing both sides by 3,

x=5

Answer: So the original number that Mike thought was 5.

Answer 2

The answer is 5 because 5 plus 17 is 22 minus 7 is 15 meaning that the answer is 5