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Bunuel
In a production lot, 20% of widgets are blue and the rest are black. One-half of widgets are made of silver and the rest are made of gold. If 10% of the widgets are silver and blue, and 80 are black and gold, how many total widgets are there?

A. 140
B. 160
C. 180
D. 200
E. 250

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.


Attachment:
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2021-01-13_13-32-13.png [ 32.53 KiB | Viewed 3515 times ]
Attachment:
2021-01-13_13-32-30.png
2021-01-13_13-32-30.png [ 39.42 KiB | Viewed 3490 times ]
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x/5 - x/10 = x/2 - 80
x = 200

D.
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Bunuel
In a production lot, 20% of widgets are blue and the rest are black. One-half of widgets are made of silver and the rest are made of gold. If 10% of the widgets are silver and blue, and 80 are black and gold, how many total widgets are there?

A. 80
B. 100
C. 160
D. 200
E. 320

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.

Attachment:
2021-01-12_01-01-10.png
2021-01-12_01-01-10.png [ 31.91 KiB | Viewed 3403 times ]
Attachment:
2021-01-12_01-01-25.png
2021-01-12_01-01-25.png [ 38.79 KiB | Viewed 3368 times ]
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