Answer: A) line segment Explanation: As parabola is a locus of a point, which moves so that its distance from focus and directrix is always equal.   The latus rectum of a conic section is the chord (line segment) that passes through the focus, is perpendicular to the major axis and has both endpoints on the curve. The length of the latus rectum is determined differently for each conic.                                          The length of a parabola's latus rectum is 4p, where p is the distance from the focus to the vertex.

Answer: C) Mesosphere Explanation: The mesosphere lies above the stratosphere and extends to an altitude of about 85 km. This is layer is often referred to as the cold layer, as the lowest readings in the atmosphere are found here.   Temperature decreases with height, reaching a minimum average value of -90 ºC at the top of the layer.

Answer: B) 11 Explanation: Half the Product of Number in the upper & lower box gives the number in the middle box. i.e. 18 x 4/2 = 36 15 x 6/2 = 45 In the same way  8 x N/2 = 44 => N = 11.

Answer: C) Rs. 1400 Explanation: We know thatThe Difference between Compound Interest and Simple Interest for n years at R rate of interest is given by C.In - S.In = PR100n Here n = 2 years, R = 20%, C.I - S.I = 56 56 = P201002=> P = 56 x 52=> P = 56 x 25=> P = Rs. 1400

The Riddle itself has the Answers. What is a 4 letter word Yet is written in 3 letters Everything is written with 9 letters Then with 4 letters Rarely has 6 letters Never is written in 5 letters.

Let the present age's of mother be 'M' and that of her son be 'S'. According to the given data in the question, M - 5 = 3(S - 5) F - 3S = -10  ...............(1) Then given , M + 5 : S + 5 = 11 : 5  => 5M - 11S = 30 ..............(2)   From (1) & (2), we get S = 20 Then by substituting S = 20 in (1) or (2), we get M = 50.   Hence, the present age of mother is M = 50 years.

Answer: D) 6 Explanation: Sum of decimal places = 7. Since the last digit to the extreme right will be zero (since 4 x 5 = 20), so there will be 6 significant digits to the right of the decimal point.

Answer: C) 9 : 10 Explanation: The ratio of X and Y ages at present is 4:5.  Then, the ratio 20 years ago will not be more than the ratio at present. So, from the options 9:10 is not satifying => its ratio is 0.9 which is greater than presnt ratio of 0.8.