KARACHI - Dollar took further strength against rupee in open market on Thursday and traded at lowest price of Rs 97.80.  According to the data provided by the Forex Association of Pakistan, dollar traded at minimum price of Rs 96.35 and maximum price of Rs 96.40 in inter bank market. On the other side it was traded at lowest rate of Rs 97.80 and highest rate of Rs 97.95 in cash free market.