Answer:

1. Rate of 10g of gold is $ 15600

2. Original price of computer is $ 36500

3. List price of TV set is $ 25000

Step-by-step explanation:

[tex]\large\underline{\sf{Solution-1}}[/tex]

Let assume that rate per 10 g of gold be $ x.

According to statement, it is given that Karuna bought 10 g of gold for $ 15756 including VAT at 1%.

So,

[tex]\sf \: x + 1\% \: of \: x = 15756 \\ \\ [/tex]

[tex]\sf \: x +\dfrac{x}{100} = 15756 \\ \\ [/tex]

[tex]\sf \: \dfrac{100x + x}{100} = 15756 \\ \\ [/tex]

[tex]\sf \: \dfrac{101x}{100} = 15756 \\ \\ [/tex]

[tex]\sf \: x = \dfrac{100}{101} \times 15756 \\ \\ [/tex]

[tex]\sf \: x = 100 \times 156 \\ \\ [/tex]

[tex]\sf\implies \sf \: x = 15600 \\ \\ [/tex]

Hence,

Rate of 10g gold is $ 15600

[tex]\rule{190pt}{2pt}[/tex]

[tex]\large\underline{\sf{Solution-2}}[/tex]

Let assume that original price of computer be $ x.

According to statement, it is given that Mohit purchased a computer for $ 37960 including VAT at 4%.

So,

[tex]\sf \: x + 4\% \: of \: x = 37960 \\ \\ [/tex]

[tex]\sf \: x +\dfrac{4x}{100} = 37960 \\ \\ [/tex]

[tex]\sf \: \dfrac{100x + 4x}{100} = 37960 \\ \\ [/tex]

[tex]\sf \: \dfrac{104x}{100} = 37960 \\ \\ [/tex]

[tex]\sf \: x = \dfrac{100}{104} \times 37960 \\ \\ [/tex]

[tex]\sf \: x = 100 \times 365 \\ \\ [/tex]

[tex]\sf\implies \sf \: x = 36500 \\ \\ [/tex]

Hence, Original price of computer is $ 36500

[tex]\large\underline{\sf{Solution-3}}[/tex]

Let assume that list price of TV set be $ x

According to statement, sale price of TV set including 8% vat is $ 27000

So,

[tex]\sf \: x + 8\% \: of \: x = 27000 \\ \\ [/tex]

[tex]\sf \: x +\dfrac{8x}{100} = 27000 \\ \\ [/tex]

[tex]\sf \:\dfrac{100x + 8x}{100} = 27000 \\ \\ [/tex]

[tex]\sf \:\dfrac{108x}{100} = 27000 \\ \\ [/tex]

[tex]\sf \:x = \dfrac{100}{108} \times 27000 \\ \\ [/tex]

[tex]\sf \:x = 100 \times 250 \\ \\ [/tex]

[tex]\sf\implies \sf \:x = 25000 \\ \\ [/tex]

Hence, List price of TV set is $ 25000.