WAEC Computer Studies 2020 Paper

Concept:To convert a decimal number to base 4, divide it repeatedly by 4 and record the remainders. The base 4 digits are the remainders written from the last division to the first.Explanation:Divide $89$ by $4$ repeatedly.$89 \div 4 = 22$ remainder $1$$22 \div 4 = 5$ remainder $2$$5 \div 4 = 1$ remainder $1$$1 \div 4 = 0$ remainder $1$Now read the remainders in reverse order, from the last remainder to the first.The remainders are $1, 1, 2, 1$.Therefore, $89_{10} = 1121_4$.Answer:$1121_4$, which is Option D.