The document you uploaded contains four problem sets, all related to basic arithmetic, including addition, subtraction, multiplication, and percentage calculations. Here's a breakdown of the problems and how to solve them:

Opgave 1 (Problem 1)

Peter is shopping for a vacation, and he buys:

• 1 t-shirt for kr. 199
• A toothbrush set for kr. 58.50
• 3 pairs of underpants at kr. 39 each

a) How much does it cost in total?

• T-shirt: 199 kr
• Toothbrush set: 58.50 kr
• 3 pairs of underpants: 3 × 39 = 117 kr
• Total cost = 199 + 58.50 + 117 = 374.50 kr

b) Peter pays with a 500 kr note. How much does he get back?

• Amount paid: 500 kr
• Total cost: 374.50 kr
• Change = 500 - 374.50 = 125.50 kr

Opgave 2 (Problem 2)

The prices at a café are listed:

• Bun with tuna: kr. 37
• Soda water: kr. 25
• Water: kr. 15
• Optional cake: kr. 23
• Ice cream with toppings: kr. 27

a) What is the price for a water, a bun with tuna, and a cake of your choice?

• Water: 15 kr
• Bun with tuna: 37 kr
• Optional cake: 23 kr
• Total = 15 + 37 + 23 = 75 kr

b) If you buy the above meal 4 times a month, how much does it cost in a year (52 weeks)?

• Monthly cost = 75 kr × 4 = 300 kr
• Yearly cost = 300 kr × 12 months = 3600 kr

Opgave 3 (Problem 3)

A class of 22 students and 2 teachers is going on a 5-day trip to Sæby, staying in cabins. The expenses per person (student/teacher) are:

• Food: kr. 65 per day
• Accommodation: kr. 85 per day
• Transport: kr. 7000 in total
• Excursions: kr. 125 per person
• Other expenses: kr. 2500 in total

a) What is the total cost of the trip?

• Food for 5 days: 65 × 5 = 325 kr per person
• Accommodation for 4 nights: 85 × 4 = 340 kr per person
• Total food and accommodation: 325 + 340 = 665 kr per person
• Transport: kr. 7000 total
• Excursions: kr. 125 per person
• Other expenses: kr. 2500 total
• Total cost = (24 people × 665 kr) + 7000 + (24 × 125) + 2500
• Total cost = 15960 + 7000 + 3000 + 2500 = 28460 kr

b) What is the cost per person? (Round to the nearest whole number)

• Total cost: 28460 kr
• Total participants: 24
• Cost per person = 28460 ÷ 24 = 1186 kr

Opgave 4 (Problem 4)

Oliver has agreed with his parents that if he leaves his confirmation money (kr. 25000) in the bank, they will give him 6% interest per year.

a) How much does Oliver have after the first year?

• Interest = 6% of 25000 = 0.06 × 25000 = 1500 kr
• Total after 1 year = 25000 + 1500 = 26500 kr

b) How much does he have after 3 years?

We use compound interest for this, where the interest is added each year to the principal amount:

• After the second year: 26500 × 1.06 = 28090 kr
• After the third year: 28090 × 1.06 = 29775.40 kr

Would you like more details on any of the steps?

5 related questions:

1. How do you calculate compound interest for more than 3 years?
2. If Peter bought an additional item costing 50 kr, how would the change from 500 kr be affected?
3. What would be the cost of the café meal if Peter added an ice cream with toppings?
4. How would the trip expenses change if only 20 students and 2 teachers went?
5. What would Oliver’s total be if the interest rate was 5% instead of 6%?

Tip: When calculating compound interest, always remember to add the interest back to the principal before calculating the next year's interest.