In particular language if A=0, B=1, C=2

 In particular language if A=0, B=1, C=2,…….. ..     , Y=24, Z=25 then what is the value of  ONE+ONE (in the form of alphabets only)

a. BDAI   
b. ABDI   
c. DABI   
d. CIDA

Answer: a
Explanation:
This problem is based on Base 26 rather than regular base 10 (decimal system) that we normally use.  In base 10 there are 10 digits 0 to 9 exist.  In base 26 there are 26 digits 0 to 25 exist.  To convert any number into base 26, we have to divide the number with 26 and find the remainder. (Study this Base system chapter).
Here, ONE + ONE =
E has value of 4. So E + E = 8 which is equal to I.
Now N + N = 13 + 13 = 26.  But in base 26, there is no 26.  So (26)10=(10)26$(26{)}_{10}=(10{)}_{26}$

So we put 0 and 1 carry over. But 0 in this system is A.
Now O + O + 1 = 14 + 14 + 1 = 29

Therefore, (29)10=(13)26$(29{)}_{10}=(13{)}_{26}$
But 1 = B and 3 = D in that system. So ONE + ONE = BDAI