Question

Jonathan finds a piece of metal that is 2 1/5 inches thick. He files off 3/10 inch. He adds a protective covering to the metal that is 2/10 inch thick. Then, he polishes the metal and removes an additional 1/10 inch. What is the final thickness of the metal?

Answer 1

The final thickness of the metal = 2 inches.

Explanation:

Jonathan finds a piece of metal that is 2
`(1)/(5)` inches thick.

The thickness of the metal = 2
`(1)/(5)` =
`(11)/(5)`

He files off
`(3)/(10)` inch,

the thickness becomes =
`(11)/(5)` -
`(3)/(10)` =
`(19)/(10)`

He adds a protective covering to the metal that is
`(2)/(10)` inch thick.

the thickness becomes,
`(19)/(10)` +
`(2)/(10)` =
`(21)/(10)`

Then, he polishes the metal and removes an additional
`(1)/(10)` inch.

The final thickness becomes,
`(21)/(10)` -
`(1)/(10)` = 2 inches