Question 53
If $$\frac{a}{b} = \frac{4}{5}$$ and $$\frac{b}{c} = \frac{15}{16}$$, then $$\frac{c^{2} - a^{2}}{c^{2} + a^{2}}$$ is:
Solution
$$a\ =\ \frac{4b}{5}$$
$$c=\frac{16b}{15}$$
Substituting these values in $$\frac{c^{2} - a^{2}}{c^{2} + a^{2}}$$
==> $$\frac{\left(\frac{16b}{15}\right)^2-\left(\frac{4b}{5}\right)^2}{\left(\frac{16b}{15}\right)^2+\left(\frac{4b}{5}\right)^2}=\frac{\frac{256}{225}-\frac{16}{25}}{\frac{256}{225}+\frac{16}{25}}=\frac{112}{400}=\frac{7}{25}$$.
Get AI Help
Create a FREE account and get:
- Download Maths Shortcuts PDF
- Get 300+ previous papers with solutions PDF
- 500+ Online Tests for Free
