Question

At the school store the cost of three markers and two pencils is exactly $2.20 while the cost of four markers and six pencils is exactly $3.40. How much would it cost to buy 1 marker and 2 pencils?

Answer 1

`\$0.92`

Explanation:

Let cost of 1 marker be
`x` and 1 pencil be
`y`

From the question we get two equations

`3x+2y=2.2\quad ...(i)`

`4x+6y=3.4\quad ...(ii)`

Multiply the first equation by 3
`(i)*3`

`9x+6y=6.6\quad ...(iii)`

`4x+6y=3.4\quad ...(iv)`

Subtracting the above equations
`(iii)-(iv)` we get

`5x=3.2\\\Rightarrow x=(3.2)/(5)\\\Rightarrow x=0.64`

`4x+6y=3.4\\\Rightarrow y=(3.4-4x)/(6)=(3.4-4* 0.64)/(6)\\\Rightarrow y=0.14`

One marker costs $0.64 and one pencil costs $0.14

Cost of 1 marker and 2 pencils is
`0.64+0.14* 2=\$0.92`.