decimals

[Julieapril]

I am working this problem:

What is 75% of 21.6?

My answer was 16.2

The book says it is 1.62

I think the book is wrong. Any help?

 

[Mrspi]

I am working this problem:

What is 75% of 21.6?

My answer was 16.2

The book says it is 1.62

I think the book is wrong. Any help?

The book IS wrong.

75% of 21.6 is the same as 0.75*21.6, which is 16.2.

 

[stapel]

I think the book is wrong.

And a quick estimation confirms it:

75% is three-fourths, and 21.6 is more than 20. But three-fourths of 20 is 15, much more than 1.62, and very close to your answer of 16.2.

Somebody typoed when writing the solutions, is all. :wink:

Eliz.

 

[pka]

Do any of you know how the “back-of-book” answers are generated?
As a undergraduate, I was a grader for a specialist in probability who wrote many texts for pre/in service teachers. Thus, I was hired by his publisher to work out the answers to the odd problems in the “back-of-book”. It was a lucrative deal; at $0.25 per problem (this was forty years ago). BUT NO ONE checked my work! I hate to think how many mistakes that I may have made.