The Sensex at the Bombay Stock Exchange gained a modest 35 points, or 0.2 percent, to close at 16,189 on Monday, as investor sentiment was boosted by easing inflation.The Nifty at the National Stock Exchange rose 8 points, or 0.2 percent, to 4,874. Stock markets in Japan, China, Hong Kong, South Korea and Singapore lost between 1 percent and 1.5 percent, after Standard and Poor's cut the rating of nine European nations.