If $a^{1/x} = b^{1/y} = c^{1/z}$ and $a, b, c$ are in geometric progression,then $x, y, z$ are in.....

If the arithmetic mean between $p$ and $q$ $(p > q)$ is twice the geometric mean,then $p : q = .......$

If $x, 1, z$ are in $A.P.$ and $x, 2, z$ are in $G.P.$,then $x, 4, z$ will be in

If the ratio of two numbers is $9:1$,then the ratio of their geometric mean to their harmonic mean is

For two positive numbers $a$ and $b$,if $a, b$ and $\frac{1}{18}$ are in a geometric progression,while $\frac{1}{a}, 10$ and $\frac{1}{b}$ are in an arithmetic progression,then $16a + 12b$ is equal to $.........$.

If $a, b, c$ are in $A.P.$ and $a, c - b, b - a$ are in $G.P.$ $(a \ne b \ne c)$,then $a:b:c$ is