The speed of sound in hydrogen at STP is v. The speed of sound in a mixture containing 3 moles of hydrogen and 2 moles of oxygen at STP will be

Let the density of hydrogen be ρ'=2ρ, then the density of oxygen will be 32ρ . The density of the mixture will beρ"=35×2ρ+25×32ρ=14ρSince the pressure is the same, we havev"v=ρ'ρ"=2ρ14ρ=17