Need step for AQ2.3 Question 3 (Non Graded question)

[ketanba...@gmail.com]

Need step for AQ2.3 Question 3 (Non Graded question)

If the origin cuts the line segment P(-2,-4), Q(6,K)  in the ratio 1 : 3, then the value of k is ___

options

1. cannot be determined

2. 0

3. 12 <-- this is the correct answer

4. 18

[Debajyoti Biswas]

This is an easy question. Can you check the lecture videos and solution tips? If we take the ratio to be m : n then there is a formula, find it

[Ketan Barapatre]

Hey

Surely it's an easy one but unfortunately but I am struggling with it, need someone to point out my mistake.  I have watched the video and I doing calculation as below

p = (x1,y1) = (-2, -4)
q = (x2,y2) = (6, K)
x = 0 y=0 because it cuts the origin
m=1 and n=3

Using this formula y = ( (m*y2) + (n*y1) )/ m + n

Is this right?

[subhajit POD]

Yes, as you have pointed out, we will get the equation, 

(1(k)+ 3(-4))/4 =0 

Hence. k-12=0 , so you will get k =12

Hope it helps. 

Best

Subhajit