Three separate surveys of China’s factory and services sectors released on Wednesday showed stubborn weakness in the world’s second-biggest economy, putting the government’s newly minted growth target of around 7 percent for the year at risk. The official Purchasing Managers’ Index ticked up to 50.1 in March from 49.9 in February, but a separate private survey from HSBC which focuses on small and mid-sized firms showed factory activity contracted after two months of recovery.