Asked by student

Estimate 16 20/21*28 3/7 - 4 13/25 + 8 2/47 as a whole number or as a mixed number whee the fractional part is 1/2.

a. 452
b.480
c.488
d.492 1/2

I would say the answer is c - 488. Would that be right?
Answered by brie
the * means times, right?
Answered by Dk
yes
Answered by student
yes, that is what we use in class instead of x when we are are on the computer.
Answered by brie
Assuming it does, I multiplied and got 10120.alotmore#s. Did you get the same thing? Did you round after that? (I multiplied 16 20/21 and 28 3/7)
Answered by ~christina~
I really don't know if you copied the question wrong or something because when I did the question 3 times total and keyed the fractions into my calculator I get the same answer of

485.45 so I don't know if either the multiple choice is incorrect or the copied question is wrong but something is funny.
Answered by brie
What's a common denominator of 25 and 47?
Answered by ~christina~
I'm not sure but a foolproof way to go and use a denominator common to both is to go and

multiply both numbers

here: 25x47=1175
Answered by Anonymous
thanks! but now I just realized that if I find the common denominator of those two numbers, I'm not following PEMDAS, so hold on, I have to rethink this.
Answered by brie
Okay, I have to get off the computer now, but I hope this which I figured so far will help you find the answer:
I multiplied 16 20/21 and 28 3/7. I got the fraction 212532 over 21.
Next, you subtract 4 13/25 from 212532 over 21, I think. Once you've done that, add 8 2/47, and you should get a matching answer. Hopefully. Or else there's seriously something wrong about the whole question, like, it had to have been misprinted or typed incorrectly or something. Good Luck! I'll work on it more tonight and I'll check back probably tomorrow.
Answered by ~christina~
Brie the 2 fractions multiplied is NOT what you got...are you using a calculator?
Answered by ~christina~
Posting my work on this:

16 20/21*28 3/7 - 4 13/25 + 8 2/47 =

(356/21)*(199/7)-(133/25)+(378/47)=

(70844/147)-(133/25)+(378/47)=

484.654
(this is most likely the answer to <b>this</b> question that you posted [it may have been copied wrong] because I'm using my TI-83 Plus graphing calculator to just straight punch in the fractions(it can handle large fractions) while before I was using a normal calculator)

<b>note it's not there as a choice so I personally feel that it's a problem with the question/ multiple choice</b>