Question

Two kilograms of bronze costs £7.20.
What is the cost of 300g of bronze?

Answer 1

Set up your equation so that unit labels cancel out leaving you with the units needed for the solution...

300g(kg/1000g)($7.2/2kg)=$1.08

Answer 2

£1.08 is the cost of 300g of bronze

Explanation:

Proportion states that two ratio or fractions are equal.

Given the statement:

two kilograms of bronze costs £7.20.

use conversion:

1 kg = 1000 gm

then;

2 kg = 2000 gm

then;

2000 gm of bronze costs £7.20.

We have to find cost of 300g of bronze

Let x be the cost of 300 gm of bronze.

By definition of proportion we have;

`(2000)/(7.20) = (300)/(x)`

By cross multiply we have;

`2000x = 2160`

Divide both sides by 2000 we have;

⇒x = £1.08

Therefore, £1.08 is the cost of 300g of bronze