Question

riya makes a cuboid of plasticine 2cm 3cm 5cm how many such cuboid will need to form a cube

Answer 1

if she wants to make a cube the volume of cube will be a perfect cube of whole no.
so let she requires n no. of cuboids
now volume of one cuboid is
2 x 3 x 5
which is 30 cm^3
and volume of n cuboids become
n x 30 cm^3
now volume of cube = volume of n cuboids
so
a^3 = n30 cm^3
so a =
$\sqrt[3]{30n}$

now smallest perfect cube which can be generated by 30 is 27000 so
n should be 900