Chapter 7.6, Problem 41STP

To determine

To find: Which of the following represents greatest percent of change in its original quantity:

1. Boots that were original priced at $90, are on sale at $63.
2. A baby that weighted 7 pound at birth now weights 10 pounds.
3. A bracelet that costs $12 in its making, is sold for $28.
4. A saving account increased from $500 to $600 in one year.

Answer to Problem 41STP

Statement, “A bracelet that costs $12 in its making, is sold for $28.” represents the greatest percent of change in its original price. Or, statement H is correct answer.

Explanation of Solution

Given information: Following statements are given:

1. Boots that were original priced at $90, are on sale at $63.
2. A baby that weighted 7 pound at birth now weight 10 pounds.
3. A bracelet that costs $12 in its making, is sold for $28.
4. A saving account increased from $500 to $600 in one year.

Formula used: Following formula is used ( ignoring increase or decrease i.e. + or − sign)

Percent change $=\frac{\text{total change}\times 100}{\text{original amount}}$

Calculation: So, on ignoring increase or decrease,

1. Total change $=90-63=27$

So Percent change $=\frac{27\times 100}{90}=30\text{\%}$

2. Total change $=10-7=3$

So Percent change $=\frac{3\times 100}{7}=42.85\text{\%}$

3. Total change $=28-12=16$

So Percent change $=\frac{16\times 100}{12}=133.33\text{\%}$

4. Total change $=600-500=100$

So Percent change $=\frac{100\times 100}{500}=20\text{\%}$

Conclusion: By above calculation, it is cleared that greatest percent change is 133.33% that is in selling a bracelet.