Questions

Ten kids will get each one apple. The eleventh kid will get the apple with the bowl.

A book has a spine to hold all the pages, but it has no bones.

A periscope is an optical instrument that uses a system of prisms, lenses, or mirrors to reflect images through a tube.

Light from a distant object strikes the top mirror and is then reflected at an angle of 90 degrees down the periscope tube. At the bottom of the periscope, the light strikes another mirror and is then reflected into the viewer’s eye.

Hence, A periscope works by the principle of Total internal reflection.

The possessive form of pronoun ‘one’ is ‘oneself’. So the phrase ‘with himself’ needs to be replaced with ‘with oneself’ to make the sentence grammatically correct. Thus, the correct formation would be, ‘One is often pleased with oneself’.

Let their edges be a and b. Then,

a3/b3 = 1/27 (or) (a/b)3 = (1/3)3 (or) (a/b) = (1/3).

\Ratio of their surface area = 6a2/6b2 = a2/b2 = (a/b)2 = 1/9, i.e. 1:9.