COURSE MODULE NAME PERCENTAGES
COURSE MODULE NAME PERCENTAGES
COURSE MODULE NAME PERCENTAGES
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
27. According to the official 2000 census, the Hispanic population of the US in 2000 was<br />
35,305,818. It rose by an astounding 57.9% from 1990 to 2000. What was the Hispanic<br />
population in 1990?<br />
Solution:<br />
1990 → 2000<br />
old new<br />
old 35,305,818<br />
If we use the percentage change formula, then<br />
% change = (new – old) / old<br />
57.9% = (35,305,818 – old) / old<br />
doing some algebra<br />
0.579 * old = 35,305,818 – old<br />
0.579 * old + old = 35,305,818<br />
1.579 * old = 35,305,818<br />
old = 35,305,818 / 1.579<br />
old = 22,359,606<br />
28. From a news article: "In the first six months of 1996, the number of deaths [from AIDS] fell<br />
12% to 22,000 [compared to the same period a year earlier]." How many AIDS deaths were there<br />
during the first six months of 1995?<br />
Solution:<br />
1995 → 1996<br />
old new<br />
old 22,000<br />
Because there was a 12% decrease, we have to use –12%<br />
–12% = (22,000 – old) / old<br />
–0.12 * old = 22,000 – old<br />
–0.12 * old + old = 22,000<br />
0.88 * old = 22,000<br />
old = 22,000 / 0.88<br />
old = 25,000<br />
29. If 75% of a number is added to 75, the result is the number itself. Then the number is<br />
Ans.300<br />
Basic formula:<br />
X% = x / 100<br />
a/ b as percent : (a/b x 100) %<br />
Answer with explanation<br />
Take the number as x<br />
Percentages<br />
18
Change language