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

Answer: C) decrease by 4% Explanation: Here, x = 20 and y = - 20Therefore, the net % change in value=x + y + xy100 %= 20 + -20 + 20 × -20100%  or  - 4% Since the sign is negative, there is a decrease in value by 4%.

Answer: A) 2Mg + O2 ----> 2MgO Explanation: Given Equation is  Mg + O2 → MgO Balancing the Chemical Equation is nothing but Conservation of Matter. As Matter is Neither created nor Destroyed, it must be conserved. Here we have 1 Mg and 2 O on the left side and 1 Mg and 1 O on the right side To balance that, add 1 Mg on the left side so that it becomes 2 Mg and 2 O on the left side i.e, 2 Mg + O2 → 2 MgO Here it has 2 Mg & 2 O on the left side and 2 Mg and 2 O on the right side and the Chemical equation is Balanced.

Answer: C) 80% Explanation: circumference of A = 2πr = 8 => so r = 4πvolume = π×4π2×10 = 160πcircumference of B = 2πr   = 10 => so r = 5πvolume = π×5π2×8 =  200πso ratio of capacities = 160/200 = 0.8 so capacity of A will be 80% of the capacity of B.

Answer: A) Department of Transportation Explanation:

Answer: A) 29 Explanation: Let the five consecutive odd numbers be x-4, x-2, x, x+2, x+4 According to the question, Difference between square of the average of first two odd number and the of the average last two odd numbers is 396 i.e, x+3 and x-3 ⇒x + 32 - x - 32 = 396⇒ x2 + 9 + 6x - x2 + 6x - 9 = 396⇒ 12x = 396⇒ x = 33   Hence, the smallest odd number is 33 - 4 = 29.

Answer: B) 168 Explanation: we can select the 5 member team out of the 8 in 8C5 ways = 56 ways. The captain can be selected from amongst the remaining 3 players in 3 ways. Therefore, total ways the selection of 5 players and a captain can be made = 56x3 = 168 ways.   (or)   Alternatively, A team of 6 members has to be selected from the 8 players. This can be done in 8C6 or 28 ways. Now, the captain can be selected from these 6 players in 6 ways. Therefore, total ways the selection can be made is 28x6 = 168 ways.

Answer: B) 105 Explanation: First line will cut all other 14, similarly second will cut 13, and so onTotal = 14+13+12+11+10+9+8+7+6+5+4+3+2+1 = 105.