'SENSEX' is the popular Index of Bombay Stock Exchange (BSE). It is measured on the basis of how many blue chip companies listed in BSE?

1. A

   20

   (a) 20. Twenty was an older, narrower basket; today’s Sensex is not computed on twenty scrips.

2. B

   30

   (b) 30. The BSE Sensex is a free-float market-cap index of thirty large, liquid blue-chip companies listed on the Bombay Stock Exchange. That thirty-stock basket is the official key.

3. C

   25

   (c) 25. Twenty-five is not the Sensex universe; it is a distractor between twenty and thirty.

4. D

   10

   (d) 10. Ten names cannot represent the Sensex; a ten-stock gauge would be a different product.

Summary. Official key is (b) 30. Sensex, launched in 1986, tracks thirty blue chips on the Bombay Stock Exchange. It is not a twenty-, twenty-five- or ten-stock index. Nifty Fifty of the National Stock Exchange is a separate fifty-stock gauge and must not be confused with Sensex.