An organic compound undergoes first-order decomposition. The time taken for its decomposition to 1/8 and 1/10 of its initial concentration are t_1/8 and t_1/10 respectively. What is the value of $$\left[ {{{{t_{1/8}}} \over {{t_{1/10}}}}} \right] \times 10$$? ($${\log _{10}}2 = 0.3$$)

The concentration of R in the reaction R $$\to$$ P was measured as a function of time and the following data is obtained The order of reaction is

The number of neutrons emitted when $${}_{92}^{235}U$$ undergoes controlled nuclear fission to $${}_{54}^{142}Xe$$ and $${}_{38}^{90}Sr$$ is