Find the third proportional of $\frac{1}{7}$ and $\frac{3}{14}$
Answer
Third proportional to $\frac{1}{7}$ and $\frac{3}{14}$ $=\frac{\frac{3}{14} \times \frac{3}{14}}{\frac{1}{7}}=\frac{9}{196} \times \frac{7}{1}=\frac{9}{28}$
Find the third proportional of 2 m 40 cm and 40 cm
Answer
Third proportional to $2 \mathrm{~m} 40 \mathrm{~cm}$ and $40 \mathrm{~cm}$ or $240 \mathrm{~cm}$ and $40 \mathrm{~cm}$ $\frac{40 \times 40}{240}=\frac{20}{3}=6 \frac{2}{3} \mathrm{~cm}$