The Letters of A, B, C and D, do not appear
in the spellings of 1 to 99.
The ‘D’ appears 1st time in HUNDRED.
‘A’ appears 1st time in THOUSAND,
‘B’ appears 1st time in BILLION,
‘C’ appears 1st time in CRORE,
Intersting Hmmm
The Letters of A, B, C and D