Answer: D) 5 Explanation: By trial and error method, we get2880/3 = 960 is not a perfect square2880/4 = 720 is not a perfect square2880/5 = 576 which is perfect square of 24Hence, 5 is the least number by which 2880 must be divided in order to make it into a perfect square.

The sound is what can you hear but not touch or see.

Answer: A) 788 Explanation: (kx22)/100 = 340 - 166.64 = 173.36 k = (173.36 x 100)/22 k = 788

Answer: C) 4 Explanation: N = H.C.F. of (4665 - 1305), (6905 - 4665) and (6905 - 1305) = H.C.F. of 3360, 2240 and 5600 = 1120. Sum of digits in N = ( 1 + 1 + 2 + 0 ) = 4

Answer: D) Moving Explanation: In physics, we know that the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Hence, An object that has kinetic energy must be in motion i.e, moving.

Answer: C) Steel Explanation: The primary use of iron ore is in the production of iron. Most of the iron produced is then used to make steel. Steel is used to make automobiles, locomotives, ships, beams used in buildings, furniture, paper clips, tools, reinforcing rods for concrete, bicycles, and thousands of other items.

Answer: C) Amazon river Explanation: There are No bridges over The Amazon River. The Amazon River, in South America, is the largest river by discharge volume of water in the world and the second longest in length after The Nile in Egypt.

Answer: C) 71 Explanation: To find the greatest number which divides the numbers 964, 1238 and 1400 leaving the remainders 41, 31 and 51 is nothing but the HCF of (964 - 41), (1238 - 31), (1400 - 51). Therefore, HCF of 923, 1207 and 1349 is 71.