221: In India, the problem of soil erosion is associated with which of the following?
1. Terrace cultivation
2. Deforestation
3. Tropical Climate
Select the correct answer using the code given below
(a) 1 and 2 only
(b) 2 only
(c) 1 and 3 only
(d) 1, 2 and 3
222: Optical fibre works on the principle of
(a) total internal reflection
(b) refraction
(c) scattering
(d) interference
223: More than 40 Heads of States/Governments were invited by Vladimir Putin in May 2003 to:
(a) Discuss the issues related to the rehabilitation of Iraq
(b) Celebrate the tricentenary of the city of St Petersburg
(c) Convene a meeting of European and CIS countries to discuss the issue of missile shield for European and CIS countries
(d) Develop the strategies for containing global terrorism
224: The persons start walking at a steady pace of 3 km/hour from a road 1 intersection along two roads that make an angle of 60° with each other. What will be the (shortest) distance separating them at the end of 20 minutes ?
(a) 3 km
(b) 2 km
(c) 1.5 km
(d) 1 km
225: A box contains 5 sets of balls while there are 3 bails in each set. Each set of balls has one colour which is different from every other set. What is the least number of balls that must be removed from the box in order to claim with certainty that a pair of bails of the same colour has been removed?
(A) 6
(B) 7
(C) 8
(D) 9