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percentage yield questions

Hi,

I'm sure i got the concept right but i didn't get the answer right, as i did 95% off 550g on my calculator (95/100 x 550) which equaled to 522.5. After i got this answer it ruined the whole question, even though my working out was right. The mark scheme did 100/95 x 550 instead of 95/100 x 550, why is it this im probably missing something really simple in this. I'll add the question.

(edited 6 months ago)

Screenshot 2023-10-29 at 19.50.03.png105.5KB

Reply 1

Laffer

You're doing it backwards, 550g is the amount you want to end up with so you need to calculate what you have to start with assuming a 95% yield to get to 550g. I.e. what amount x 95% will yield 550:

X.(95/100)=550
Rearranged X = 550.100/95

(edited 6 months ago)