Answer: A) -1/2 Explanation: Rewrite equation as 122x+1 = 120   Leads to 2x + 1 = 0    Solve for x : x = -1/2

Answer: C) 2/21 Explanation: Given that there are three blue marbles, four red marbles, six green marbles and two yellow marbles.   Probability that both marbles are blue = ³C₂/¹⁵C₂ = (3 x 2)/(15 x 14) = 1/35 Probability that both are yellow = ²C₂/¹⁵C₂ = (2 x 1)/(15 x 14) = 1/105 Probability that one blue and other is yellow = (³C₁ x ²C₁)/¹⁵C₂ = (2 x 3 x 2)/(15 x 14) = 2/35   Required probability = 1/35 + 1/105 + 2/35 = 3/35 + 1/105 = 1/35(3 + 1/3) = 10/(3 x 35) = 2/21

Answer: A) Terrace cultivation Explanation: Hence, soil erosion on hillslopes can be checked by Terrace cultivation.

Answer: D) Intel Explanation:

Answer: B) 6 kmph Explanation: Speed of the stream = 1Motor boat speed in still water be = x kmphDown Stream = x + 1 kmphUp Stream = x - 1 kmph[35/(x + 1)] + [35/(x - 1)] = 12x = 6 kmph

Answer: B) Rs. 6000 Explanation: The wages of labourers in a factory increases in the ratio 22:25 and there was a reduction in the number of labourers in the ratio 15:11. Find the original wage bill if the present bill is Rs 5000 ?Ratio of increase of wages = 22:25Ratio of decrease of labourers = 15:11Compound ratio of wages of labourers = 22 x 15 : 25 x 11 = 330:275Final bill = Rs. 5000For 275 ratio wages = Rs. 5000For 1 ratio wages = 5000/275For 330 ratio wages = 5000/275 x 330 = Rs. 6000

Answer: D) Gulf of California Explanation: A gulf in geography is a large bay that is an arm of an ocean or sea.   The second smallest sea on Earth is the Sea of Cortez, more commonly called the Gulf of California. This sea is about 62,000 square miles. It lies between Mexico and the Baja California Peninsula.

Answer: A) 9 Explanation: Speed in still water = Average of Speed in Upstream and speed in Downstream = 1/2 (12 + 6) kmph = 9 kmph.