• # question_answer The bricks of dimension $\mathbf{15cm}\times \mathbf{25cm}\times \mathbf{7cm}$ required to build a wall $\left( \mathbf{3}.\mathbf{5}\times \mathbf{10}\times \mathbf{12} \right){{\mathbf{m}}^{\mathbf{3}}}$are A)  160000B)  170000         C)  180000                        D)  200000

(a): no. of bricks = $\frac{\left( 3.5\times 100 \right)\times \left( 10\times 100 \right)\times \left( 12\times 1400 \right)}{15\times 25\times 7}$ (All dimensions converted into cm) $=\frac{3.5\times 10\times 12}{15\times 25\times 7}=1000000$ $=\frac{60}{15\times 25}\times 1000000=160000.$