Joy is planning to purchase a sweater that costs $30 dollars at her local department store. the sweaters are on sale for 20% off. which steps are needed to find the sale price of the sweater?
a. convert the percent to its decimal equivalent. multiply the decimal by the original amount to find the discount.
b. convert the percent to its decimal equivalent. divide the decimal by the original amount to find the discount. subtract the discount from the original amount.
c. convert the percent to its decimal equivalent. multiply the decimal by the original amount to find the discount. add the discount to the original amount.
d. convert the percent to its decimal equivalent. multiply the decimal by the original amount to find the discount. subtract the discount from the original amount.

The average human heart beats 1.15 \cdot 10^51.15⋅10 5 1, point, 15, dot, 10, start superscript, 5, end superscript times per day. there are 3.65 \cdot 10^23.65⋅10 2 3, point, 65, dot, 10, start superscript, 2, end superscript days in one year.how many times does the heart beat in one year? write your answer in scientific notation, and round to one decimal place.

The rate of decay of a radioactive substance depends upon the amount present initially. the mass y (mg) of the radioactive substance cobalt-60 present in a sample at time t (years) is represented by the exponential equation y=50e −0.1315 t . answer the following questions in complete sentences. 1. how does the exponential equation above compare to the equation for simple interest that is compounded continuously? explain the similarities. 2. what is the initial amount of cobalt-60 in the sample? 2. how much cobalt-60 is left after 8.4 years? show your work. 3. what would be the y-intercept of the graph? what does it represent? 4. after how many years will the amount of cobalt-60 left be 6.25 mg? explain what happens to the cobalt-60 after 50 years? 5. discuss some “real-world” examples and uses of cobalt-60

How many times larger is 6 × 10^12 than 2 × 10^7? a. 30,000 b. 3,000 c. 3,000,000 d. 300,000