In the given figure, OA = 5, OB = 6, OC = 3 and OD = 10, then

1. Δ AOB ∼ Δ AOB

2. Δ AOB ∼ Δ BOC

3. Δ BOC ∼ Δ COD

4. Δ AOD ∼ Δ COB

Given,

OA = 5, OB = 6, OC = 3 and OD = 10.

$\Rightarrow \dfrac{OA}{OC} = \dfrac{5}{3} \\[1em] \Rightarrow \dfrac{OD}{OB} = \dfrac{10}{6} = \dfrac{5}{3} \\[1em] \therefore \dfrac{OA}{OC} = \dfrac{OD}{OB}$

From figure,

∠AOD = ∠BOC (Vertically opposite angles are equal)

∴ △ AOD ∼ △ COB (By S.A.S. axiom)

Hence, option 4 is the correct option.