Sales of single-family homes and condominiums on Oahu rose by double digits in May, as prices posted single-digit gains, according to statistics release Monday by Honolulu real estate firm Locations. There were 376 single-family homes sold last month, a 12 percent increase from 335 homes sold in May 2016, Locations said. The median price of a single-family home in May was $750,000, which was 4 percent higher than the median price a year ago, which was $719,000. The median price of a condominium …