Answer: A) 5 Explanation: The following arrangements satisfy all 3 conditions. Arrangement 1: 3 books in a row; 12 rows. Arrangement 2: 4 books in a row; 9 rows.Arrangement 3: 6 books in a row; 6 rows.Arrangement 4: 9 books in a row; 4 rows.Arrangement 5: 12 books in a row; 3 rows.   Therefore, the possible arrangements are 5.

Answer: B) 24 kmph Explanation: Average speed=total distance/total timeLet distance to store be  Kthen, total time =(K/20)+(K/30)=K/12and, total time =(2K)so average speed= 2K / (K/12) = 24kmph.

Answer: B) 30 Explanation: 332 + 3 = 12552 + 5 = 30

Answer: C) Rs. 7000 Explanation: Let the sum be Rs. S.(S x 18 x 2)/100 - (S x 12 x 2)/100 = 840 => 36S/100 - 24S/100 = 840 => 12S/100 = 840 => S = 7000.

Answer: B) Proton Explanation: Protons carry a positive electrical charge, electrons carry a negative electrical charge and neutrons carry no electrical charge at all. The protons and neutrons cluster together in the central part of the atom, called the nucleus, and the electrons 'orbit' the nucleus.

Answer: B) 1/2 Explanation: We know that: When one card is drawn from a pack of 52 cards The numbers of possible outcomes n(s) = 52 We know that there are 26 red cards in the pack of 52 cards⇒ The numbers of favorable outcomes n(E) = 26 Probability of occurrence of an event: P(E)=Number of favorable outcomes/Numeber of possible outcomes=n(E)/n(S) ∴ required probability = 26/52 = 1/2.

Answer: A) CaO Explanation: An ionic bond is a chemical bond between two atoms in which one atom seems to donate its electron to another atom.   Here in the given compounds, the compound that contains ionic bond is CaO, Calcium oxide.

Answer: D) 360 mts Explanation: Speed of the Train K is given by s = d/t = 240/20 = 12 m/sDistance covered by Train K in 50 seconds = 12 x 50 = 600 mts.But it crosses Train L in 50 seconds Therefore, the length of the Train L is = 600 - 240 = 360 mts.