Finding Month & Day of Date of Birth of a Person (Funny Maths)

Procedure:
1. Consider the month number of the date of birth (1 for January, 2 for February, 3 for March 4 for April,..)
2. Double it.
3. Add 5 to answer.
4.  Multiply the answer by 5.
5. Multiply  the answer by 10.

6. Add day if the date of birth to answer.
7. Tell the final answer to the speaker.

Example:
1. Consider the month number of the date of birth (9 for September)
2. Double it. (9*2=18)
3. Add 5 to answer. (18+5=23)
4.  Multiply the answer by 5. (23*5=115)
5. Multiply  the answer by 10. (115*10=1150)
6. Add day if the date of birth to answer. (25 as day of date of birth-1150+25=1175)
7. Tell the final answer to the speaker. (1175)

Solution:
 Divide Answer in to two parts. First part is unit and 10 place digit. Second part 100th or 1000th place ( if exist). In above example 11/75. 75-50=25, Corresponds to  Day of date of birth. 11-2= 9, Corresponds to  Month of date of birth. So September 25 is the Answer. This is true for all the cases. If first part is less than 50 speaker should reply  "You Made Mistake