Question

If points P(1,2) ,Q(0,0) and R(a,b) ,then

(a) a = b

(b) a = 2b

(c) 2a = b

(d) a = -b

Answer 1

As the question incomplete,
Assuming that the points P, Q and R are collinear.

So, the area of ΔPQR is 0

Area of triangle = $\frac{1}{2}|x_1(y_2-y_3) + x_2(y_3-y_1)+x_3(y_1-y_3)|$

                      0 = $\frac{1}{2}|1(0-b) + 0(b-2)+a(2-0)|$
                         
                     0  = $|-b + 0+ 2a|$
 
                     2a = b

Option C is correct answer.