1 Evaluate 202 2 three - 112 2 three - WAEC Mathematics 2004 Question

(202^2_{three})when converted to base ten (=(202_3)^2<br /> 202_3 = 2 \times 3^2 + 0 \times 3^1 + 2\times 3^0 = 18 + 0 + 2<br /> =20_{ten}; (202_3)^2 = (20)^2_{ten} = 400<br /> 112^2_{three})when converted to base ten (= (112_3)^2<br /> 112_3 = 1 \times 3^2 + 1 \times 3^1 + 2\times 3^0 = 9+3+2=14_{ten}<br /> (112_3)^2 = (14)^2_{ten} = 196_{ten}<br /> Evaluate \Longrightarrow 400-196 = 204)
Reconvert to base three
(\begin{matrix}
3 & 204\
3 & 69 &R0\
3 & 22 & R2\
3 & 7 & R1\
2 & 2 & R1<br /> & 0& R2 \uparrow<br /> \end{matrix} <br /> =21120_3)