ruplun wrote:Could you please solve this DS problem ...
Of the companies surveyed about the skills they
required in prospective employees, 20 percent
required both computer skills and writing skills. What
percent of the companies surveyed required neither
computer skills nor writing skills?
(1) Of those companies surveyed that required
computer skills, half required writing skills.
(2) 45 percent of the companies surveyed required
writing skills but not computer skills.
I'm hoping that everyone will be able to follow the explanation below without the benefit of a Venn diagram.
Since we're looking only for a percentage, we can plug in that we have 100 companies. Of these 100 companies, some will require only computer skills, some only writing skills, some both computer and writing skills, some neither computer nor writing skills.
100 = (only computer) + (only writing) + (both computer and writing) + (neither computer nor writing)
What do we want?
neither computer nor writing
What do we know?
both computer and writing = 20
What do we need?
only computer skills and only writing
Only computer = total computer - both computer and writing
Only writing = total writing - both computer and writing
Statement 1:
If both computer and writing = 1/2 total computer, then 20 = 1/2(total computer), and total computer = 40. So only computer = 40 - 20 = 20. But we still don't know the number that require only writing skills. INSUFFICIENT.
Statement 2:
Only writing skills = 45. But we still don't know the number that require only computer skills. INSUFFICIENT.
Statements 1 and 2 together:
Only computer skills = 20
Only writing skills = 45
Plugging into the equation at the top, we get:
100 = 20 + 45 + 20 + (neither computer nor writing)
So neither computer nor writing = 100 - 20 - 45 - 20 = 15.
SUFFICIENT.
The correct answer is C.
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