The uncertainty in velocities of two particles $\mathrm{A} \text{and} \mathrm{B} \text{are} 0.05 \text{and} 0.02 \mathrm{m}/\mathrm{s}$ respectively. The mass of $\mathrm{B}$is five times to that of the mass of $\mathrm{A}$. What is the ratio of uncertainty $\frac{∆{\mathrm{x}}_{\mathrm{A}}}{∆{\mathrm{x}}_{\mathrm{B}}}$ in their position?

The de-Broglie wavelength of an electron travelling at $\mathrm{x}$percent of the speed of light was found to be $2.42 \stackrel{\mathrm{o}}{\mathrm{A}}$. Then, what is the value of '$\mathrm{x}$'?

Suppose that the maximum number of electrons in a d-orbital is '$\mathrm{x}$' and the minimum number of electrons of the same spin in 'd' sub-shell (of any possible configuration) is '$\mathrm{y}$'. Then, what is the product '$\mathrm{xy}$'?