WAEC Mathematics 2012 Paper

Concept:To change a base-10 number into base 2, divide the number repeatedly by 2 and note the remainders.Explanation:Start with $35$ and divide by $2$, writing the quotient and the remainder.$35 \div 2 = 17$ remainder $1$$17 \div 2 = 8$ remainder $1$$8 \div 2 = 4$ remainder $0$$4 \div 2 = 2$ remainder $0$$2 \div 2 = 1$ remainder $0$$1 \div 2 = 0$ remainder $1$Now read the remainders from the last division upward to the first division.This gives the binary number $100011_2$.Answer:$35_{10} = 100011_2$Option C is the correct answer.