Do you know,
-------->Letters 'a', 'b', 'c' &'d' do not appear anywhere in the spellings of 1 to 99
--------> Letter 'd' comes for the first time in Hundred
-------->Letters 'a', 'b' & 'c' do not appear anywhere in the spellings of 1 to 999
--------> Letter 'a' comes for the first time in Thousand
-------->Letters 'b' & 'c' do not appear anywhere in the spellings of 1 to 999,999,999
-------->Letter 'b' comes for the first time in Billion
-------->Letter 'c' does not appear anywhere in the spellings of entire English counting
