Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : The number of parallelograms in a chess board is 1296. Reason R : The number of parallelograms when a set of m parallel lines is intersected by another set of n parallel lines is \({}_𝑚𝐶^2, {}_𝑛𝐶^2\) In the light of the above statements, choose the correct answer from the options given below:Step-by-step Solution:
A standard chessboard consists of an 8 × 8 grid, meaning it has 9 horizontal and 9 vertical lines. \[ {}_9C^2 \times {}_9C^2 = 36 \times 36 = 1296 \] Since the given formula correctly calculates this, both Assertion (A) and Reason (R) are true, and R correctly explains A.