how many bricks each of length 25 cm , and 12 cm , would be required to field a courtyard of 30 m long and 20 m wide?
area of brick = .25*.12 = .03 m^2
area of yard = 20*30 = 600 m^2
number of bricks = 600/.03 = 20,000
area of yard = 20*30 = 600 m^2
number of bricks = 600/.03 = 20,000