arithmetic Nr 65 of the maths bool

[reiserchen]

Quote
of 3,500 items manufactured by a machine, 80 percent pass the initial quality control , and the rest require additional resting. how many more items pass the initial quality control than those which require additinal resting
Unquote

3500 x 0,2 = 700 require additional test.

But the answer is 2,100 with the explaination: the quantity required is 2,800 - 700 = 2100.

Honestly, it seems I don't get the question right. why do you need to subtract the 700 from the one, which passed already the inital quality control?

Can you explain, what I have missed?
Thanks and regards
wolfgang

[kevin]

The question is not asking how many require further testing, but rather how many more pass the initial testing than require further testing.

Another example: In club of 200 members, 55% of the members smoke. How many more members are non-smokers than smokers?

[reiserchen]

o.k. finally I got it.

But I would say, your 2nd questions has no answer unless the question is" How many more members are smokers than non-smokers?

answer: 20!

thanks and cheerio