Volume of the triangular prism = BaseArea×Height
A = Area of triangle =12×base×height=12×3×4=6 cm2
Volume of prism =6×h
=6×15
=90 cm3
It is melted into cubes of side 1 cm
Let n be the no. of cubes obtained
Volume of prism = =n× volume of each cube
90 =n×(1 cm)3
n=90
Hence, 90 cubes are cast from the prism.