Successive discounts of 10%, 20% and 30% is equivalent to single discount of?

Here, r₁ = 10 %, r₂ = 20% and r₃ = 30%
∴ Required discount
= [1 - (1 - r₁/100) (1 - r₂/100) (1 - r₃/100)] x 100%
= [1 - (1 -10/100) (1 - 20/100) (1 - 30/100)] x 100%
= {1 - (9/10) x (4/5) x (7/10)} x 100%
= (1 - 0.504) x 100% = 49.6%