536: Which one among the following countries has the lowest GDP per capita?

(a) China
(b) India
(c) Indonesia
(d) Sri Lanka
537: Which one of the following is also called Stranger Gas?

(a) Argon
(b) Nitrous oxide
(c) Xenon
(d) Neon
538: On multiplying a number by 3, the product is a number each of whose digits is 7. What is the smallest such number?
539: Which of the following is a cash crop ?

(a) Groundnut

(b) Wheat

(c) Rice

(d) Gram
540: Which one of the following statements is correct?

(a) Cirrus clouds are composed of ice crystals.
(b) Cirrus clouds exhibit a flat base and have the appearance of rising domes.
(c) Cumulus clouds are white and thin, and form delicate patches and give a fibrous and feathery appearance.
(d) Cumulus clouds are classified as high clouds.