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, PR⊥QT

∴  b–4a–5×–6/54=–1 ⇒ b–4a–5×310=1

⇒ 10a–3b=38          ... (i)

Also, PS⊥QR

∴  –6/5–3×b–4a+2=–1

⇒ 5a+2b=–2          ... (ii)

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

a = 2, b = - 6

Now, centroid of △PQR = (c, d)

⇒ (5–2+23,4+4–63)=(c,d)

⇒ c=53, d=23

∴  c+2d=53+43=3.