Question

If the points (k, 2k), (3k, 3k) and (3,1) are collinear, then k

a. 1/3
b. -1/3
c. 2/3
d. -2/3

Answer 1

(3k - 1)/(3k - 3) = (3k - 2k)/(3k - k)

(3k - 1)/(3k - 3) = 1/2

2(3k - 1) = 3k - 3

6k - 2 = 3k - 1

3k = 1

k = 1/3

The correct answer is A.