Determine the order of each of the following quotient groups.
($U(25)$ is the group of units in $\mathbb{Z}_{25}$, $D_{10}$ denotes the dihedral group of order 20, and $Q_8$ is the quaternion group.)

$\mathbb{Z}_{68} / \langle36\rangle$
order =

$U(25) / \langle 4\rangle$
order =

$D_{10} / \langle a^{4}\rangle$
order =

$Q_8 / \langle i\rangle$
order =