Answer:
1) 337; 2) 1364; 3) 31.
Explanation:
1) 223/8=27*8+7 - the underlined number 7 is in result; the number 27 is in the next step:
27/8=3*8+3 - the underlined number 3 is in result; the number 3 is in the next step:
3 - the number 3 is in result (cannot divided by 8).
Finally, the result is 337₈ (not 733).
2) 2f4₁₆ is possible to imagine in binary: 2₁₆ as 0011₂; f₁₆ as 1111 and 4₁₆ as 0100₂;
then rewrite (0011 1111 0100)₂ as (001 011 110 100)₂, then to convert every group consists of 3 digits: 001₂=1₁₀; 011₂=3₁₀; 110₂=6₁₀ and 100₂=4₁₀.
Finally, (001 011 110 100)₂=1364₁₀.
3) if to divide the given binary number into groups by 3 symbols, then it can be written 11001₂= (11 001)₂ or (011 001)₂. Then if to write every group in dec form, then 011₂=3₁₀ and 001₂=1₁₀.
Finally, (011 001)₂=31₁₀.
PS. note, the given way is not the shortest one.