Convert the following between octal, decimal and hexadecimal

Question

(a) Convert $61502$ from base $8$ to decimal.

(b) Convert $EB7C5$ from base $16$ to octal.

My answer: a) $6\times8^4+1\times8^3+5\times8^2+\times8^1+2\times8^0=25410$

b) not sure: converting $E=14$, $B=11$ and $C=12$ we have $14117125$. I needed hints here.

Answer 1

The rule for b) is to first convert into decimal base(i.e. multiply by powers of 10) and then convert them to Octal (remainders when dividing by 8)

Answer 2

A) is just fine.

B)

$15*16^4+11*16^3+7*16^2+12*16+5=$

$15*2^{16}+11*2^{12}+7*2^8+12*2^4+5=$

$15*2*8^5+11*8^4+7*4*8^2+12*2*8+5=$

$30*8^5+(8+3)*8^4+28*8^2+24*8+5=$

$(3*8+6)*8^5+8^5+3*8^4+(3*8+4)*8^2+3*8^2+5=$

$3*8^6+7*8^5+3*8^4+3*8^3+7*8^2+5=$

$3733705$.