Correct option is (b) 19cm*9cm*9cm
To explain I would say: For India, a brick of standard size 190 mm x 90 mm x 90 mm is recommended by the BIS. With mortar thickness, the size of such a brick becomes 200 mm x 100 mm x 100 mm and it is known as the nominal size of the modular brick. Thus the nominal size of brick includes the mortar thickness.
It is found that the weight of 1 cum of brick earth is about 18 KN. Hence the average weight of a brick will be about 30 to 35 N.
