Answer: A) nonpolar, with a symmetrical distribution of charge Explanation: CF4 is tetrahedral. Since the four 'F' atoms have the same electronegativity values, there is no bias in electron distribution toward any one.   Therefore, electron/charge distribution is symmetrical, which also means that the molecule is nonpolar.   Hence, CF4 is nonpolar molecule with a symmetrical distribution of charge.

Answer: A) 5 kmph Explanation: Let p be the speed of man in kmph According to the given data in the question, Distance travelled by bus in 10 min with 20 kmph == Distance travelled by man in 8 min with (20 + p) kmph in opposite direction => 20 x 10/60 = 8/60 (20 + p) => 200 = 160 + 8p => p = 40/8 = 5 kmph.

In chemistry, a product is a substance that is formed as the result of a chemical reaction. In a reaction, starting materials called reactants and the ending materials are called products.

Answer: D) Opossum Explanation: The shortest gestation period known is 12 to 13 days, shared by three marsupials: the American or Virginian opossum (Didelphis marsupialis); the rare water opossum, or yapok (Chironectes minimus) of central and northern South America; and the eastern native cat (Dasyurus viverrinus) of Australia. Gestation is the period of time between fertilization and birth in oviparous animals. The elephant has the longest gestation period of about 23 months of any land animal.

Answer: A) 15:07 hrs Explanation: Next train comes at 17:00 hrs.So, last train will be = 17:00hrs - 2:30hrs= 14:30hrsAnnouncement made after 37 min of the last train.S0, 14:30hrs + 00:37 min= 15:07 hrs.

Answer: D) 51 Explanation: Unit digit of this expression is always 1 as the base ends with 1.  For the tenth place digit we need to multiply the digit in the tenth place of the base and unit digit of the power and take its unit digit. i.e, tenth place digit in 2151 is 5 and tenth place digit in power 415 is 1 And the units digit in the product of 5 x 1 = 5   Therefore, last two digits of 2151415 is 51.

Answer: B) 60 Explanation: The given digits are 1, 2, 3, 5, 7, 9   A number is even when its units digit is even. Of the given digits, two is the only even digit.Units place is filled with only '2' and the remaining three places can be filled in ⁵P₃ ways.   Number of even numbers = ⁵P₃ = 60.

Answer: D) Ar Explanation: Argon is most the most abundant Rare Gas in the atmosphere. Its elemental symbol is Ar.