Given:
Selling price of a machine = 7000/-
Gross loss = 20%.
To find:
The cost and gross loss.
Solution:
Let x be the cost of machine.
According to the question,
![x-20\%\text{ of }x=7000](https://img.qammunity.org/2021/formulas/mathematics/college/asn0d95icumbiir64p8440qzrsbousw78w.png)
![x-(20)/(100)x=7000](https://img.qammunity.org/2021/formulas/mathematics/college/aij94q64rwx5409f649wnhkltb61lnn8ra.png)
![x-0.2x=7000](https://img.qammunity.org/2021/formulas/mathematics/college/gy4o65l9b0w93arvs2icfrcwahs0r4gtc6.png)
![0.8x=7000](https://img.qammunity.org/2021/formulas/mathematics/college/6lu1cx63bx8ipuenjh6115xek0b7v0qi6j.png)
Divide both sides by 0.8.
![x=(7000)/(0.8)](https://img.qammunity.org/2021/formulas/mathematics/college/tom6s6tj1lrj4lokmvh8mca9nbi1lpnbtn.png)
![x=8750](https://img.qammunity.org/2021/formulas/mathematics/college/mofl6kf7ml9sn6wgzysbj7uiuf0a1oq83w.png)
So, the cost of the machine is 8750/-.
Now,
![\text{Gross Loss}=\text{Cost}-\text{Selling price}](https://img.qammunity.org/2021/formulas/mathematics/college/9wbv374nm3yl7m7rsu8aizfzgte6jb5p93.png)
![\text{Gross Loss}=8750-7000](https://img.qammunity.org/2021/formulas/mathematics/college/jm6nyhg7w4uzblswf717s8ctn4enkmbiea.png)
![\text{Gross Loss}=1750](https://img.qammunity.org/2021/formulas/mathematics/college/lwzxaugnbs51xvlsaqgreqiookkqa5mrvd.png)
Therefore, the gross loss is 1750/-.