Of the teams competing in the world archery championships...

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Of the teams competing in the world archery championships, twenty percent are from Europe. Half as many are from the United States and one twentieth are from Africa. What fraction of teams are from neither Europe, the US or Africa?

A. 13/20
B. 15/20
C. 13/15
D. 17/20
E. 13/17

The OA is A.

Please, can any expert explain this PS question for me? I tried to solve it but I can't get the correct answer and I would like to know how to solve it in less than 2 minutes. I need your help. Thanks.
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by [email protected] » Sun Jan 21, 2018 11:15 am
Hi swerve,

We're told that of the teams competing in the world archery championships, twenty percent are from Europe, half as many are from the United States and one twentieth are from Africa. We're asked for the fraction of teams that are NOT from Europe, the US or Africa. This question ultimately comes down to converting data from one format to another and some basic arithmetic.

Based on the information given, we know:
20% = 20/100 of the teams are from Europe
Half of that =10% = 10/100 of the teams are from the U.S.
1/20 = 5% = 5/100 of the teams are from Africa

20/100 + 10/100 + 5/100 = 35/100 = 7/20 of the teams are from those 3 areas

Thus, 1 - 7/20 = 13/20 of the teams are NOT from those 3 areas.

Final Answer: A

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by Jeff@TargetTestPrep » Tue Jan 23, 2018 9:13 am
swerve wrote:Of the teams competing in the world archery championships, twenty percent are from Europe. Half as many are from the United States and one twentieth are from Africa. What fraction of teams are from neither Europe, the US or Africa?

A. 13/20
B. 15/20
C. 13/15
D. 17/20
E. 13/17
We can let the total number of teams = 100

Thus, 20 are from Europe, 10 are from the US, 5 are from Africa,

So, 100 - 20 - 10 - 5 = 65 are from neither Europe, the US or Africa, which is 65/100 = 13/20.

Answer: A

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