Assertion and Reason Type

Directions : In each of the following questions, a statement of Assertion is given followed by a corresponding statement of Reason just below it. of the statements, mark the correct answer as

(a) If both assertion and reason are true and reason
is the correct explanation of assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If assertion is false but reason is true.​

Assertion : The external dimensions of a wooden
box are 18 cm, 10 cm and 6 cm respectively and thickness of the wood is 5 mm, then the internal
volume is 765 cm3.

Reason : If external dimensions of a rectangular box be I, b and h and the thickness of its sides be x, then its internal volume is (1- 2x)(b- 2x) (h- 2x).