Question

The perimeter of a rectangular metal plate is 15 cm. Find the length of the rectangular plate (in decimals) whose width is 228 cm. Use estimation in tenths place.

Answer 1

The Solution.

Representing the problem in a diagram, we have

By formula,

`P=2(L+W)`

In this case,

Substituting these values in the formula above, we get

`15=2(L+(22)/(8))`

Clearing the bracket, we get

`15=2L+(2*(22)/(8))`
`\begin{gathered} 15=2L+(11)/(2) \\ \\ 15=2L+5.5 \end{gathered}`
`\begin{gathered} 15-5.5=2L \\ 9.5=2L \end{gathered}`

Dividing both sides by 2, we get

Therefore, the correct answer is option C.