)×10=5:6 B is common in both ratio so you can equal the ratio of B. A : B = (8 : 9) × 2 = 16 : 18 C : B = (5 : 6) × 3 = 15 : 18 A : B : C = 16 : 18 : 15 Let the value of A, B and C be 16x, 18x and 15x. 16x – 15x = 121 ⇒ x = 121 B = 18x = 18 × 121 √B=11×3√2=33√2m ∴ Required answer √B is 33√2m.