# If three cubes whose edges measure 3 cm, 4 cm and 5 cm are melted

If three cubes whose edges measure 3 cm, 4 cm and 5 cm are melted and made into a cube, then the edge of the new cube (in cms) is …….

(a) 9

(b) 8

(c) 7

(d) 6

Total volume of 3 cubes = (3^{3 }+ 4^{3 }+ 5^{3 }) cm^{3}

= (27 + 64 + 125)cm^{3}

= 216 cm^{3}

Now volume of new cube = 216 cm^{3}

So edge of new cube = cube root of 216 cm^{3}

= 6 cm