Q.

Let the area of a PQR with vertices P(5, 4), Q(–2, 4) and R(a, b) be 35 square units. If its orthocenter and centroid are O(2,145) and C(c, d) respectively, then c + 2d is equal to          [2025]

1 2  
2 3  
3 73  
4 83  

Ans.

(2)

Since, PRQT

  b4a5×6/54=1  b4a5×310=1

 10a3b=38          ... (i)

Also, PSQR

  6/53×b4a+2=1

 5a+2b=2          ... (ii)

Solving equations (i) and (ii), we get

a = 2, b = - 6

Now, centroid of PQR = (c, d)

 (52+23,4+463)=(c,d)

 c=53, d=23

  c+2d=53+43=3.