Australian teen Mollie O’Callaghan set a new world record in winning the women’s 200m freestyle in a time of 1min, 52.85sec at swimming’s world championships on Wednesday.The 19-year-old finished ahead of fellow Australian Ariarne Titmus on 1:53.01 and Canadian Summer McIntosh on 1:53.65.Titmus led for most of the race but O’Callaghan reeled her in over...