Gap Inc (NYSE:GPS) shares are rising in extended trading Thursday on the heels of the company’s first-quarter financial results. Q1 Revenue: $3.39 billion, versus estimates of $3.29 billionQ1 EPS: 41 cents, versus estimates of 14 centsComparable sales were up 3% year-over-year. Store sales were up 3%, while online sales jumped 5%. Merchandise margin increased 340 basis points compared to the prior year. Gap said it ended the quarter with $1.7 billion in cash, equivalents and short-term investments. “Gap Inc. delivered a strong quarter that exceeded expectations across key metrics. We gained ma…