Silver Gold total
Blue 0.1 0.1 0.2t

Black 0.4t 80 0.8t

Total 0.5 0.5 t

0.8t-0.4t=80

T =200

D

Kindly refer the image below:

We know that 80 widgets are black and gold, which is equal to 40%
So total = 80/.40 = 200

Veritas Prep Official Explanation

Problems like this are intimidating without a defined method. Because the two sets of information given are complementary (meaning they account for all possibilities; every widget is either black or blue and every widget is either silver or gold) you should set up a Matrix Box, as shown. First fill in all the percent information given:



As you can see, by inserting that information you can now fill in everything else:



Now you can leverage the fact that 80 widgets are black and gold to determine the total. 80 = 40% of the total, so 80 = .4T and T = 200.



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x/5 - x/10 = x/2 - 80
x = 200

D.
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Veritas Prep Official Explanation

Problems like this are intimidating without a defined method. Because the two sets of information given are complementary (meaning they account for all possibilities: Every widget is either black or blue, and every widget is either silver or gold) you should set up a Matrix Box as shown below. First fill in all the percent information given:



As you can see, by inserting that information you can now fill in everything else:



Now you can leverage the fact that 80 widgets are black and gold to determine the total. 80 = 40% of the total, so 80 = .4T and T = 200.


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