three cubes of metal whose edges are 9 , 12 and 15 cm respectively , are melted and one new cube is made . find the edge of the new cube ?
"93 + 123 + 153 = a 3 = > a = 18 answer : d"
power(add(add(volume_cube(9), volume_cube(12)), volume_cube(15)), const_0_33)