The histogens are classified on the basis of

If the system of linear equations $x + 2ay + az = 0$,$x + 3by + bz = 0$,and $x + 4cy + cz = 0$ has a non-zero solution,then $a, b, c$:

What is the time (in $sec$) required for depositing all the silver present in $125 \ mL$ of $1 \ M \ AgNO_3$ solution by passing a current of $241.25 \ A$? $(1 \ F = 96500 \ C)$

If $A+2 B=\begin{bmatrix} 1 & 2 & 0 \\ 6 & -3 & 3 \\ -5 & 3 & 1 \end{bmatrix}$ and $2 A-B=\begin{bmatrix} 2 & -1 & 5 \\ 2 & -1 & 6 \\ 0 & 1 & 2 \end{bmatrix}$,then $\operatorname{Tr}(A)-\operatorname{Tr}(B) = $

The locus of the centre of the circle,which cuts the circle $x^2+y^2-20x+4=0$ orthogonally and touches the line $x=2$,is