Answer: C) 20 Explanation: Given (2a + 3b)/(5a - 3b) = 23/5 => 10a + 15b = 115a - 69b=> 105a = 84b => 5a = 4b a/b = 4/5 => a=4 & b=5=> bxa = 5x4 = 20.

Answer: C) 9620 Explanation: As the interest rate increases by 2%=> (7000x3x2)/100 = 420                                   9200                                  --------                                   9620

Answer: B) 60 degrees Explanation: Given the angles of a quadrilateral are in the ratio of 2:4:7:5Let the angles of a quadrilateral are 2x, 4x, 7x, 5xBut we know that sum of the angles = 360 degrees.=> 2x + 4x + 7x + 5x = 360=> x = 20Therfore, the smallest angle of the quadrilateral = 2x = 2x20 = 40 degrees.One of the angle of the triangle = 2 x 40 = 80 degreesThe other angle is 180 - (40 + 80) = 60 degrees. Hence the second largest angle of the triangle is 60 degrees.

Answer: B) Glucose Explanation: Since A polymer is a large molecule, or macromolecule, composed of many repeated subunits. Glucose is not a polymer.

Answer: A) 22 yrs Explanation: Let Reena’s present age be 'K' yrs.Given:{(K+3) x 4} - {(K-3) x 3)} => K = 21 yrsSo her present age is 21 yrs.Then, her age after 1 year is 22 yrs.

Answer: D) In the adult heart, blood in the right chambers of the heart cannot enter the left chambers without passing through the lungs. Explanation: In the adult heart, blood in the right chambers of the heart cannot enter the left chambers without passing through the lungs is correct regarding mammalian heart.

Answer: D) 8 months Explanation: Let the total Profit be Z.Ramu's profit share is 2/3 of profit (i.e 2Z/3)Ravi's profit is (Z-2Z/3) =Z/3Hence the profit ratio is , Ravi : Ramu = Z/3 : 2Z/3 = 1:2 Let total Capital be Rs.X and Ramu has contributed for Y months.Since Ramu's profit share is 2/3, his invest share will be 2/3 in capital. Ravi's invest for 16 months / Ramu's invest for Y months = Ravi's profit share / Ramu's profit sharei.e. (X/6 x 16) / (2X/3 x Y) = 1/2 Solving the above equation, we get Y = 8.So Ramu's money has been used for 8 months.

Answer: D) Milk Explanation: Milk is not a pure substance since it has so many constituents that can be separated physically. Compounds are pure substances formed from elements unlike mixtures.