Question

Giovanna used the calculations below to determine the height of a stack of 7 books that are each 2 5/8

inches thick what
was her error?
C. There should be a subtract step not an addition step
D. Two should have been multiplied by 5/8

Answer 1

Option B.

Explanation:

Giovanna did the calculations to determine the height of a stacks of 7 books having
`2(5)/(8)` inches thickness of each book.

`7(2(5)/(8))`

`=7(2+(5)/(8))`

`=(7* 2)+7((5)/(8))`

`=14+(35)/(8)`

`=14+4+(3)/(8)`

=18+
`(3)/(8)`

`=18(3)/(8)`

Now when compare this solution with Giovanna's solution we find error in 3rd step, in which she hasn't mutiplied the fraction
`(5)/(8)` by 7.

Therefore, option B is the correct one.

Answer 2

Option C. Seven was not multiplied by 5/8

Explanation:

we know that

To determine the height of a stack of 7 books that are each 2 5/8 inches thick. multiply 7 by 2 5/8

so

`7(2(5)/(8))\\ \\7(2+(5)/(8))\\ \\7*2+7*(5)/(8)\\ \\14+(35)/(8)\\ \\14+4+(3)/(8)\\ \\18(3)/(8)\ in`

therefore

Seven was not multiplied by 5/8