Question

John thinks of a number. He deducts 12 from it and then divides the result 1 point
by 9. His answer is 9. What number did he start with?

Answer 1

Answer:

Let the number be x

I think we can work it out according to the statement without considering BODMAS.

SO,

{((X+7)×3-3)÷2}×12=72

{(3x+21–3)÷2}×12=72

{(3x+18)÷2}×12=72

By rearranging this we get

3x+18=(72×2)÷12

3x+18=12

3x=12–18

3x=-6

X=-6÷3

X=-2

Proof

-2+7=5

5×3=15

15–3=12

12÷2=6

6×12=72

Answer 2

Answer:

John started with number 93

Step-by-step explanation:

Let the number John thought be $x$.

Step 1 : Deduct 12

Result 1 : $(x - 12)$

Step 2 : Divides Result 1 by 9

Result 2 : $\frac{(Result \ 1)}{9}$= $\frac{x - 12}{9}$

Final Answer of John = 9

==> $\frac{x-12}{9} \ = \ 9 \\x-12 \ = \ 9 \ * \ 9 \\x-12 \ = \ 81 \\x \ = \ 81 + 12\\x \ = \ 93$