For an investment compounded continuously, the rule of 69 gives a better approximation than the rule of 72 (for normal compound interests).
To solve this problem you must apply the proccedure shown below:
1. She has a total of 50 DVDs of 90 minutes each one of them. The cost of each DVD was 11€.
2. Therefore, to calculate the total cost of the collection, you must multiply the cost of each DVD by the total number of them:
€
3. To calculate the total minutes of the collection, you must multiply 90 minutes by the total number of DVDs:

Therefore, the answer is: 550€ and 4500 minutes.
Answer:
60 percent
Step-by-step explanation:
6 black socks, 4 white socks, 10 socks altogether, 60 percent of the socks are black, so is the chance of picking both black socks