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: 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) 26 July Explanation:

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

Answer: D) 20 years Explanation: Present total age of the members = 26(5) = 130 years.   Present age of the youngest member = 10 years   Present total age of the remaining four members = 130 -10 = 120 years   Their average age at the time of the birth of the youngest member = 120-4×104 = 30 - 10 = 20 years.

Answer: D) 2 hrs Explanation: Speed in downstream = 96/8 = 12 kmph Speed of current = 4 km/hr Speed of the boatman in still water = 12 – 4 = 8 kmph Speed in upstream = 8 – 4 = 4 kmph Time taken to cover 8 km upstream = 8/4 = 2 hours.

Answer: D) 6630 Explanation: Let first no. be "k" and multiple be "l"...start value of y with 3then,[(k x y) + {l x (l-1)}]Thus, we get 15 x 3 + 3 x 2 = 5151 x 4 + 4 x 3 = 216216 x 5 + 5 x 4 = 11001100 x 6 + 6 x 5 = 66306630 x 7 + 7 x 6 = 46452 Therefore, the missing number is 6630.

Answer: C) Larva Explanation: A Bill becomes a Law; a Larva becomes an insect. (Or) A Bill turns into a law; a Larva turns into an Insect.