I don't understand this at all. Please help!!!Thank you.

1.	I don't understand this at all. Please help!!!Thank you.
Answer» Topic Binary Binary is a number system of base 2. Digits of binary consist of 0 and 1. DIGIT by digit, the exponent of the base grows by 1. Example) $1_{(2)}=1$ , $10_{(2)}=2$ , $100_{(3)}=4$ , …. Since the question is giving $$ and $\bullet$ as digits, the GIVEN number system is binary. For example, 4 is 100₍₂₎ in binary. So it will be $\bullet\ \ $ in the given form. Solution 43. $\bullet\ \bullet\ \bullet$ is added to $\bullet\ \ $ . ⇒ $111_{(2)}$ is added to $100_{(2)}$ . $\implies 111_{(2)}+100_{(2)}=1011_{(2)}$ ⇒ (b)* $\bullet\ \ \bullet\ \bullet$ is the required option. 44. Which binary number represents 15? Via the repeated division by 2 method, we find the number in the binary form. $\implies 15=1111_{(2)}$ ⇒ (c)* $\bullet\ \bullet\ \bullet\ \bullet$ is the required option. 45. If $11100_{(2)}$ is divided by $111_{(2)}$ , we are dividing $28$ by $7$ of decimal. $\implies 4=100_{(2)}$ ⇒ (a) $\bullet\ \ $ is the required option. 46. Which number represents 20? $\implies 20=10100_{(2)}$ ⇒ (d) $\bullet\ \ \bullet\ \ $ is the required option. 47. Which number represents 15% of 80? Firstly, in decimal, the required number is $80\times \dfrac{15}{100} =12$ . Via the repeated division method, we find $12$ in the binary form. $\implies 12=1100_{(2)}$ ⇒ (b)* $\bullet\ \bullet\ \ $ is the required option. More Information In the repeated division by 2 method, we use the REMAINDER and the last quotient. The name is because of dividing the quotient repeatedly by 2.

Answer»