Which of the following statements is correct with regard to the reflection of light by a spherical mirror?
a) A convex mirror converges the light rays incident parallel to its principal axis.
(b) A concave mirror converges the light rays incident parallel to its principal axis.
(c) Convex mirror can form both, real and virtual images.
(d) Concave mirror can form both, real and virtual images.
The Forest Department changed its strategy, making a beginning in the Arabari forest range of Midnapore district, at the insistence of a far-seeing forest officer named:
A certain number of people are sitting in a row, facing north. Q is second to the right of P. Only three people sit between Q and S. T is fourth to the right of S. If two other persons are sitting in the row, what is the total number of people seated in the row?
Select the option that is related to the fifth number in the same way as the second number is related to the first number and the fourth number is related to the third number.
15 : 20 :: 13 : 14 :: 11 : ?