The cycloalkene (X) on bromination consumes one mole of bromine per mole of (X) and gives the product (Y)  in which C : Br ratio is 3 : 1. The percentage of bromine in the product (Y) is _______ %. (Nearest integer)
(Given : Molar mass in g mol^–1 H : 1, C : 12, O : 16, Br : 80 )