Given:
The ratio of one metre of polyester fabric to the cost of one metre of cotton fabric is 2 : 7.
The cost of 2m of polyester fabric is £4.
To find:
The costs of polyester fabric and cotton fabric for lengths of 2m, 6m, 8m, and 9m.
Solution:
The ratio of one metre of polyester fabric to the cost of one metre of cotton fabric is given.
Assume the value of 2m of cotton fabric is x.
Applying the ratio we get;
![(2)/(7) = (4)/(x) .](https://img.qammunity.org/2021/formulas/mathematics/middle-school/uc6qnrlfts83hv2sblhcogkcmu60t893yx.png)
![x=(4) (7)/(2) = 2(7)= 14.](https://img.qammunity.org/2021/formulas/mathematics/middle-school/iovxne4t2qc22fkkw1fmx0c7ba0jaz3p20.png)
So 2m of cotton fabric costs £14.
1m of polyester fabric costs
.
1m of cotton fabric costs
![(14)/(2) = 7.](https://img.qammunity.org/2021/formulas/mathematics/middle-school/9i361972djxk4hmmdqk8hbsiug2h7vvgxr.png)
So the costs of polyester fabric for 6m, 8m, 9m are
![6(2)=12, 8(2) = 16, 9(2)=18.](https://img.qammunity.org/2021/formulas/mathematics/middle-school/x9roxl9cd1qhw98icqgvgpz3qhlj6t3p4p.png)
So the costs of cotton fabric for 6m, 8m, 9m are
![6(7)=42, 8(7) = 56, 9(7)=63.](https://img.qammunity.org/2021/formulas/mathematics/middle-school/7qkaahlvb4ftf3u75lubkl6pp8remmdxcd.png)
2m of polyester fabric costs £4.
6m of polyester fabric costs £12.
8m of polyester fabric costs £16.
9m of polyester fabric costs £18.
2m of cotton fabric costs £7.
6m of cotton fabric costs £42.
8m of cotton fabric costs £56.
9m of cotton fabric costs £63.