Sara makes a cuboid having sides 15cm and 30cm. how many such cuboids will be needed to form a cube

cuboid=3*3*5 [i. e l*b*h]

LCM of 3,5=15

i. e 15cm is the dimension of the final cube.

therefore cuboid required across length=15/3=5

similarly, across breadth=15/3=5

similarly, across height=15/5=3

Therefore total no of cuboid=5*5*3=75