In a new hypothetical system of units, the new unit of mass is $5 \mathrm{kg}$, new unit of length is $10 \mathrm{m}$ and new unit of time is $20 \mathrm{s}$. Choose the correct statement(s).

Suppose two students are trying to make a new measurement system so that they can use it like a code measurement system and others do not understand it. Instead of taking $1 \mathrm{kg}, 1 \mathrm{m}$ and $1 \mathrm{s}$ as basic units, they took unit of mass as $\alpha$ $\mathrm{kg}$, the unit of length as $\beta$ $\mathrm{m}$ and unit of time as $\gamma$ $\mathrm{s}$. They called power in the new system as $\mathrm{ACME}$. Then match the two columns.

Match column $\mathrm{I}$ with column $\mathrm{II}$ and mark the correct option from the given codes. Some physical quantities are given in column $\mathrm{I}$ and some $\mathrm{SI}$ units in which these quantities may be expressed are given in column $\mathrm{II}$. Match the physical quantities in column $\mathrm{II}$ and select the code.

A stone is lying at rest in a river. The minimum mass of stone, $m=k \rho v^x{g}^{-3}$ is needed for remaining at rest. Here, $k=$ constant having no unit, $g=$ acceleration due to gravity, $v=$ river flow velocity and $\rho =$ density of water. Find the value of $x$.