Difference between revisions of "1998 AJHSME Problems/Problem 17"
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| − | ==Don't | + | ==Don't Crowd the Isles== |
Problems 15, 16, and 17 all refer to the following: | Problems 15, 16, and 17 all refer to the following: | ||
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</center> | </center> | ||
| − | + | ==Problem 17== | |
In how many years, approximately, from 1998 will the population of Nisos be as much as Queen Irene has proclaimed that the islands can support? | In how many years, approximately, from 1998 will the population of Nisos be as much as Queen Irene has proclaimed that the islands can support? | ||
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<math>\text{(A)}\ 50\text{ yrs.} \qquad \text{(B)}\ 75\text{ yrs.} \qquad \text{(C)}\ 100\text{ yrs.} \qquad \text{(D)}\ 125\text{ yrs.} \qquad \text{(E)}\ 150\text{ yrs.}</math> | <math>\text{(A)}\ 50\text{ yrs.} \qquad \text{(B)}\ 75\text{ yrs.} \qquad \text{(C)}\ 100\text{ yrs.} \qquad \text{(D)}\ 125\text{ yrs.} \qquad \text{(E)}\ 150\text{ yrs.}</math> | ||
| − | ==Solution== | + | ==Solution 1== |
We can divide the total area by how much will be occupied per person: | We can divide the total area by how much will be occupied per person: | ||
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<math>\frac{24900 \text{ acres}}{1.5 \text{ acres per person}}=16600 \text{ people}</math> can stay on the island at its maximum capacity. | <math>\frac{24900 \text{ acres}}{1.5 \text{ acres per person}}=16600 \text{ people}</math> can stay on the island at its maximum capacity. | ||
| − | We can divide | + | We can divide 16600 by the current population in <math>1998</math> which is 200 to see by what factor the population increases: |
<math>\frac{16600}{200}=83</math>-fold increase in population. | <math>\frac{16600}{200}=83</math>-fold increase in population. | ||
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It takes <math>4\times25=100=\boxed{C}</math> years to triple the island's population four times in succession. | It takes <math>4\times25=100=\boxed{C}</math> years to triple the island's population four times in succession. | ||
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| + | ==Solution 2== | ||
| + | |||
| + | We can continue the pattern, and because the pattern increases numbers rapidly, it won't be hard. <math>\frac{24900 \text{ acres}}{1.5 \text{ acres per person}}=16600 \text{ people}</math> can live on the island at its maximum capacity. | ||
| + | |||
| + | <math>1998: 200 \text{ people}</math> | ||
| + | <br> | ||
| + | <math>2023: 600 \text{ people}</math> | ||
| + | <br> | ||
| + | <math>2048: 1800 \text{ people}</math> | ||
| + | <br> | ||
| + | <math>2073: 5400 \text{ people}</math> | ||
| + | <br> | ||
| + | <math>2098: 16200 \text{ people}</math> | ||
| + | <br> | ||
| + | After the year <math>2098</math>, it will not be possible for the next increase to occur, because when <math>16200</math> is tripled, it is way more than the maximum capacity. | ||
| + | <br> | ||
| + | Thus, the answer is <math>2098-1998 = 100</math>, or <math>\boxed{C}</math> | ||
== See also == | == See also == | ||
Latest revision as of 13:30, 29 May 2021
Don't Crowd the Isles
Problems 15, 16, and 17 all refer to the following:
In the very center of the Irenic Sea lie the beautiful Nisos Isles. In 1998 the number of people on these islands is only 200, but the population triples every 25 years. Queen Irene has decreed that there must be at least 1.5 square miles for every person living in the Isles. The total area of the Nisos Isles is 24,900 square miles.
Problem 17
In how many years, approximately, from 1998 will the population of Nisos be as much as Queen Irene has proclaimed that the islands can support?
Solution 1
We can divide the total area by how much will be occupied per person:
can stay on the island at its maximum capacity.
We can divide 16600 by the current population in 
which is 200 to see by what factor the population increases:
-fold increase in population.
Thus, the population increases by a factor 
. This is very close to 
, and so there are about 
triplings of the island's population.
It takes 
years to triple the island's population four times in succession.
Solution 2
We can continue the pattern, and because the pattern increases numbers rapidly, it won't be hard. can live on the island at its maximum capacity.
After the year 
, it will not be possible for the next increase to occur, because when 
is tripled, it is way more than the maximum capacity.
Thus, the answer is 
, or 
See also
| 1998 AJHSME (Problems • Answer Key • Resources) | ||
| Preceded by Problem 16 |
Followed by Problem 18 | |
| 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | ||
| All AJHSME/AMC 8 Problems and Solutions | ||
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. 
