For a first order reaction, intercept of the graph between $$\mathrm{\log\frac{[A]_o}{[A]_t}}$$(Y-axis) and conc. (X-axis) is equal to

What is the half-life of a first order reaction if time required to decrease concentration of reactant from 1.0 M to 0.25 M is 10 hour?

What is the rate of disappearance of B in following reaction? $$2 \mathrm{A}+\mathrm{B} \rightarrow 3 \mathrm{C}$$, if rate of appearance of $$\mathrm{C}$$ is $$1.3 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$$.

What is the rate of appearance of $$\mathrm{Z}$$ in following reaction? $$3 \mathrm{x} \rightarrow 2 \mathrm{y}+\mathrm{z}$$, if rate of disappearance of $$\mathrm{x}$$ is $$0.072 \mathrm{~mol} \mathrm{~s}^{-1}$$