What number am I thinking?

Level 1

100

I think of a number. I double my number and add 5 the answer is 25.
What number is it?

10

200

I am thinking of a number. If I multiply my number by 2 and add 6 the answer is 12. What is it?

3

300

I think of a number. I multiply my number by 3 and add 3 the answer is 60.

19

400

I decided to add 6 to my number, then multiply the result by 3, After that, I subtracted 6 and doubled the result. The answer is 102.

13

500

If I multiply my number by 5 and subtract 4 then multiply the result by 2, the answer is 2 less than 194.

20

Level 2

100

I can think of a number. I double my number and add 8.6 the answer is 17

4.2

200

I am also thinking of a number. If I multiply my number by 2 and add 8.6 the answer is 18.4

4.9

300

I think of a number. I multiply my number by 3 and add 3.4 the answer is 9.4.

2

400

I decided to add 2.3 to my number then multiply the result by 3, After that I subtracted 5.2 then doubled the result. The answer is 32.2.

4.8

500

If I multiply my number by 7.4 and subtract 5.5 then multiply the result by 5.4, the answer is 7.1 less than 225.152.

6.2

Level 3

100

I think of a number. I double my number and add 21 the answer is 11'
What number was Isaiah first thinking of

-5

200

I am thinking of a number, added 7, multiplied by 3, subtracted 3, divided by 2, then multiplied by 12.The result is 72.

-2

300

I am thinking of a number. When I added 8 to the number and multiplied 2 by the same number, I got the same result. What number am I thinking of?

8

400

I am thinking of a number. When I subtracted it by 9, I doubled the result.  Lastly, I divide it by -2 and the result is -4. 

13

500

I am thinking of a number, I added -3 and multiplied by -2, the result was 8. What is the number?

-1