Bases?

[reov3596]

I don't even know what category this falls into.. I took a screenshot of it because I don't know how to type this in lol. Can someone explain how to do it?

http://oi43.tinypic.com/3462crk.jpg

 

[Deleted member 4993]

I don't even know what category this falls into.. I took a screenshot of it because I don't know how to type this in lol. Can someone explain how to do it?

http://oi43.tinypic.com/3462crk.jpg

You are doing addition in 8_base system.

You have to add 512 and 177

These go excatly like decimal system - except 7+1 becomes 10.

so:

What is 7 + 2 in 8_base system?

 

[soroban]

Hello, reov3596!

$\displaystyle \text{What is the sum of }512_8\text{ and }177_8\,?$

. . $\displaystyle (A)\;601_8 \qquad (B)\;701_8 \qquad(C)\;711_8 \qquad (D)\;611_8 \qquad (E)\;612_8$

Do you know anything about Number Bases?
If not, giving you the answer won't help
. . and explaining how would take too long.


Assuming you know something, here's one solution.


We have: .$\displaystyle \begin{array}{ccccc} & 5 & 1 & 2\;_8 \\ + & 1 & 7 & 7\;_8 \\ \hline \end{array}$


Convert to base-ten: .$\displaystyle \begin{array}{ccccccc} 512_8 &=& 5(8^2) + 1(5) + 2(1) &=& 330 \\ 177_8 &=& 1(8^2) + 7(8) + 7(1) &=& 127 \end{array}$

Add: .$\displaystyle \begin{array}{cccc}& 3&3&0 \\ +& 1&2&7 \\ \hline &4&5&7\end{array}$


Convert to base-8: .$\displaystyle 457 \;=\;771_8\;\text{ answer (C)}$