Question

A straight line through `p` and `q` is drawn perpendicular to a line through points `p(x,y)` and `r(x,(y+10))`. The possible coordinates of the point `q` are? (a). `(17,y)` (b). `(-1,y)` (c). `(0,y)` (d). All of these choices

Answer 1

Answer is `(d)`.

Explanation:

Observe that abscissa in `P(x,y)` and `R(x,(y+10))` is same. This means that `PR` is parallel to `y`-axis.

As a straight line through `P` and `Q` is drawn perpendicular to this line,

line `PQ` must be parallel to `x`-axis

and hence, ordinate of `P` and `Q` must be same

As ordinate of `P` is `y`, all points `(17,y),(-1,y)` and `(0,y)` can be `Q` and hence

Answer is `(d)`.