We can use the simple interest formula \(\displaystyle I = Prt\), substituting \(\displaystyle P = 12,000, r = 0.06, t = 5\):

\(\displaystyle I = \$ 12,000 \cdot 0.0 6 \cdot 5 = \$3,600\)

The savings account will have \(\displaystyle \$ 12,000+ \$3,600 = \$15,600\).

4% of 3,268 can be calculated by multiplying 3,268 by 0.04, the decimal equivalent of 4%:

\(\displaystyle 3,268 \times 0.04 = ?\)

Multiply 3,268 by 4, then move the decimal point two places to the right:

\(\displaystyle 3,268 \times 4 =13,072\),

so

\(\displaystyle 3,268 \times 0.04 = 130.72\)

Rounded to the nearest whole number -  131 signatures.

When the 100 dollar shirt is discounted 20%, it will be discounted 20 dollars, leaving the price at 80 dollars. 

When 80 dollars is then discounted another 25%, that value is equal to another 20 dollars. 

100 dollars less 20 dollars, less another 20 dollars is 60 dollars. 

Thus, 60 dollars is the final price. 

40% of the voters were registered as independents, so 60% were registered as a member of a political party. Since 60% of the voters numbered 15,934, we can find the total number of voters by setting up and solving a proportion:

\(\displaystyle \frac{60}{100} = \frac{15,934}{N}\)

\(\displaystyle 60 N = 100 \cdot 15,934\)

\(\displaystyle 60 N = 1,593,400\)

\(\displaystyle 60 N \div 60= 1,593,400 \div 60\)

\(\displaystyle N= 26,556.7\)

which rounds to 26,557 voters.

2% of the voters were registered as members of other parties, and 40% were unaffiliated, so we want to calculate 42% of 17,856, or, equivalently, 

\(\displaystyle 17,856 \times 0.42 = 7,499.52\)

which, to the nearest whole number, rounds to 7,500 voters.

Paying at a 15% discount is equvalent to paying 85% of the original price, so $196.57 is 85% of the original (non-employee) price, or, equivalently, 0.85 times that price. If \(\displaystyle N\) is that price, then we can set up and solve the equation:

\(\displaystyle 0.85 N = 196.57\)

\(\displaystyle 0.85 N \div 0.85 = 196.57 \div 0.85\)

\(\displaystyle N= 231.26\)

A non-employee would pay $231.26 for the groceries.

This can be solved using a proportion:

\(\displaystyle \frac{10}{100}=\frac{3}{x}\)

Cross multiply and solve for \(\displaystyle x\):

\(\displaystyle 10x=300\)

\(\displaystyle \frac{10x}{10}=\frac{300}{10}\)

\(\displaystyle x=30\)

When Susan's mother agreed to match her savings plus fifty percent, she agreed to give Susan \(\displaystyle \small 100\)% plus \(\displaystyle \small 50\)%.  

\(\displaystyle \small 100+50=150\)

Before multiplying by the amount Susan saved, we must convert \(\displaystyle \small 150\)% to a decimal by dividing by \(\displaystyle \small 100\).

\(\displaystyle \small 150/100=1.5\)

Now we multiply \(\displaystyle \small 1.5\) time $\(\displaystyle \small 600\).

\(\displaystyle \small 1.5\cdot 600=900\)

Susan's mother owes her $\(\displaystyle \small 900\).

Since the jeans are the only item being purchased, and they cost $\(\displaystyle \small 50\), we must first find \(\displaystyle \small 16\)% of $\(\displaystyle \small 50\).  In order to do that we multiply $\(\displaystyle \small 50\) by the decimal form of \(\displaystyle \small 16\)%, which is \(\displaystyle \small .16\).

Note: In order to find the decimal form of a percent, we divide it by \(\displaystyle \small 100\).  \(\displaystyle \small 16/100 = .16\)

Find the tax:

 \(\displaystyle \small .16\cdot 50 = 8\)

Therefore the sales tax added to the original price is $\(\displaystyle \small 8\). 

\(\displaystyle \small 50+8= 58\)

The final cost of the jeans is $\(\displaystyle \small 58\).

To find the answer you must first convert the sales percentage to a decimal by moving the decimal left two places yielding \(\displaystyle 25\%=.25\)

Then multiply the total cost by the decimal \(\displaystyle \$15(.25)=\$3.75\).

We then subtract the sales number from the original cost to get the answer:

\(\displaystyle \$15.00-\$3.75=\$11.25\)