Question

What is the decimal equivalent of the octal number $217$?

• A. $140$
• B. $143$
• C. $150$
• D. $155$

Answer 1

The correct option is B

$143$

Explanation of correct option:

Given binary number is $217$.

Octal to the decimal conversation is obtained by multiplying $8$ to the power of the base index along with the value at that index position.

To find the decimal equivalent of the octal number, multiply each digit of the binary number by the corresponding power of eight and add.

$217=8^2\left(2\right)+8^1\left(1\right)+8^0\left(7\right)$

$\Rightarrow$ $217=64\left(2\right)+8\left(1\right)+1\left(7\right)$

$\Rightarrow$ $217=128+8+7$

$\Rightarrow$ $217=143$

Thus, the decimal equivalent of the octal number $217$ is $143$.

Hence, the correct option is $B)143$.