how many paying stones , each measuring 2 1 / 2 m * 2 m are required to pave a rectangular court yard 30 m long and 16 1 / 2 m board ?
"30 * 33 / 2 = 5 / 2 * 2 * x = > x = 99 answer b"
divide(multiply(30, add(16, divide(1, 2))), multiply(add(2, divide(1, 2)), 2))