Question

A cuboid of plasticine of sides 5cm,2cm,5cm. How many such cuboids will he need to form a cube
How to find the cube root of 1331 without prime factorizing.

Answer 1

Dimensions of Cuboid =5,2,5
say the length of cube is 'a' units
Volume of Cuboid = $5\times 2\times 5=50c{m}^3$
Volume of cube =$a^{3}c{m}^3$
No. of cuboids needed to form the cube =$\left(\frac{a^3}{50}\right)$
Since, you have not given the dimension of the cube,
(2) Cube root of 1331
Make a group of 3 digits 1 331
The first group is 331 will give you the unit digit of the cube root i.e. 1
Now, take the 2nd group
$1^3=12^3=8$
2o, we cannot mole more than 1 as $8>1$
$\therefore$ Tens digits is 1
So, the number is 1
i.e, ${11}^3=1331$
Another eqs 857375
857 375
unit digit of cube root =5
Also, $9^3<857<{10}^3$
$\therefore$ 95 Ans