Question

xy is a perfect cube and 1000 < xy < 8000.If Y equal to 729 find cube root of x

Answer 1

X=8. Hence cube root of x =2

Answer 2

xy is a perfect cube and 1000<xy<8000. If y= 729. The x=8 and the cube root of x=2.

Stepwise explanation is given below:

- As it is given that Y=729

There are two equations

(1). 1000<xy

=1000/729<x

=1.3<x

(2). xy<8000

=x<8000/729

=x<10.9

So, the x is between 1-10

- It is also given that xy is perfect cube.

So we will try no. From 1-10 *729 till we get a perfect cube

- For example 2*729=1458

The cube root of 1458 is 11.33

So, it 2 is not the x

- You can try all

The x=8

As 8*729=5832, it is perfect cube of 18.

So, the cube root of 8 is 2.