3803: In a tournament each of the participants was to play one match against each of the other participants. 3 players fell ill after each of them had played three matches and had to leave the tournament. What was the total number of participants at the beginning, if the total number of matches played was 75 ?
(A) 12
(B) 10
(C) 8
(D) 15
3804: Given below is a map of some countries which were parts of the erstwhile Soviet Union with water bodies shown by shaded areas :
The countries marked 1, 2, 3, 4 and 5 are respectively
(a) Tajikistan, Turkmenia, Uzbekistan, Kirgizia, Kazakhstan
(b) Turkmnia, Kirgizia, Tajikistan, Uzbekistan, Kazakhstan
(c) Kazakhstan, Uzbekistan, Tajikistan, Kirgizia, Turkmenia
(d) Kazakhstan, Turkmenia, Uzbekistan, Kirgizia, Tajikstan
3805: There is some concern regarding the nanoparticles of some chemical elements that are used by the industry in the manufacture of various products. Why?
1. They can accumulate in the environment, and contaminate water and soil.
2. They can enter the food chains.
3. They can trigger the production of free radicals.
Select the correct answer using the code given below.
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3