1.
a) if (a mod 10 = 5)or(a div 100 = 5) or (a div 10 mod 10 = 5) then write('Yes')
else write('No');
b) if (a mod 10 = a div 100) then write('Yes')
else write('No');
c) if (a mod 10 <=a div 10 mod 10 = 5)and (a div 10 mod 10 <= a div 100) then write('Yes')<br>else write('No');