A school bus picking up children in a colony of flats stops at every sixth block of flats. Another school bus starting from the same place stops at every eighth blocks of flats. Which is the first bus stop at which both of them will stop$?$

For the following pair of numbers, verify the property:

Product of numbers $=$Product of their$\mathrm{H}.\mathrm{C}.\mathrm{F}$ and $\mathrm{L}.\mathrm{C}.\mathrm{M}$

$25, 65$

For the following pair of numbers, verify the property:

Product of numbers $=$Product of their$\mathrm{H}.\mathrm{C}.\mathrm{F}$ and $\mathrm{L}.\mathrm{C}.\mathrm{M}$

$117, 221$

For the following pair of numbers, verify the property:

Product of numbers $=$Product of their$\mathrm{H}.\mathrm{C}.\mathrm{F}$ and $\mathrm{L}.\mathrm{C}.\mathrm{M}$

$35, 40$

For the following pairs of numbers, verify the property:

Product of numbers $=$Product of their$\mathrm{H}.\mathrm{C}.\mathrm{F}$ and $\mathrm{L}.\mathrm{C}.\mathrm{M}$

$87, 145$

For the following pair of numbers, verify the property:

Product of numbers $=$Product of their$\mathrm{H}.\mathrm{C}.\mathrm{F}$ and $\mathrm{L}.\mathrm{C}.\mathrm{M}$

$490, 1155$

Find the $\mathrm{H}.\mathrm{C}.\mathrm{F}$ and $\mathrm{L}.\mathrm{C}.\mathrm{F}$ of $117$ and $221$.