Question

The cost of 2 jackets and 3 skirts was sh 1800. After the cost of a jacket and that of a skirt was increased by 20%,the cost of 6 jackets and 2 skirts was sh4800,what is the new cost of a jacket and that of a skirt

Answer 1

New cost of jacket =
`1.2x=1.2* 600=720\ \text{sh}`

New costs of skirt =
`1.2y=1.2* 200=240\ \text{sh}`

Explanation:

Let original cost of jacket =
`x`

original cost of skirt =
`y`

The equation will be

`2x+3y=1800`

New cost of jacket =
`1.2x`

New costs of skirt =
`1.2y`

The equation will be

`6(1.2x)+2(1.2y)=4800\\\Rightarrow 7.2x+2.4y=4800`

The equations are

`2x+3y=1800`
`* 0.8`

`7.2x+2.4y=4800`

`1.6x+2.4y=1440`

`7.2x+2.4y=4800`

Subtracting the above two equations we get

`-5.6x=-3360\\\Rightarrow x=(3360)/(5.6)\\\Rightarrow x=600`

`7.2* 600+2.4y=4800\\\Rightarrow y=(4800-7.2* 600)/(2.4)\\\Rightarrow y=200`

New cost of jacket =
`1.2x=1.2* 600=720\ \text{sh}`

New costs of skirt =
`1.2y=1.2* 200=240\ \text{sh}`.