Find the value using suitable properties:
a) 40 x 197 x 40 - 2 x 97 x 800

Dear Santanu,
Here is the answer for your query.

(40 x 40) x 197} - (2 x 800) x 97}
=(1600 x 197) - (1600 x 97)
=1600 x (197 - 97)
=1600 x 100
=1,60,000
Therefore,the answer is 1,60,000