5 lb., percentages

[nkleinmarkman]

Question #48 on percentages, page 491. I'm wondering if it would be possible to see a more detailed answer. I keep doing the multiplication myself and getting a different answer than the one in the book. It would be helpful if someone could outline the steps to reach 2x and .4x as the answers. Thanks

[n00bpron00bpron00b]

0 < x < 100

Quantity A:

x% of 0.5% of 40,000

(x/100) * (0.5/100) * 40,000

cancelling 4 zero's from the denominator with 4 zero's of 40,000 we get,

(x) * (0.5) * 4

=> 2x

Quantity B:

0.05% of 2,000% of 40x

(0.05/100) * (2,000/100) * 40x

cancelling 4 zero's from the denominator with 3 zero's of 2,000 and 1 zero of 40x we get

(0.05) * (2) * 4x

=> 0.4x

Quantity A : 2x
Quantity B : 0.4x

and 0 < x < 100

Since "x" is non-zero and positive , we can cancel out "x" from both columns

Quantity A : 2
Quantity B : 0.4

or

try plugging in values ; for all sets of values between the range greater than 0 and less than 100 ; column A will always be greater

Quantity A : 2 x
Quantity B : 0.4x

A is greater

[tommywallach]

Isn't Noob the best?

-t