If x = log $\dfrac{3}{5}, \text{ y = log } \dfrac{5}{4}\text{ and z = 2 log } \dfrac{\sqrt{3}}{2}$, the value of x + y - z is :

1. 1

2. -1

3. 2

4. 0

If log v + log 3 = log π + log 4 + 3 log r, the value of v in terms of r and other constants is :

1. $\dfrac{4}{3}πr^3$

2. 4πr²

3. πr³

4. $\dfrac{4}{3}πr^2$

If log₁₀ 8 = 0.90; find the value of :

(i) log₁₀ 4

(ii) log $\sqrt{32}$

(iii) log 0.125

If log 27 = 1.431, find the value of :

(i) log 9

(ii) log 300