Let's go through the math problems on the sheet one by one.

Opgave 1:

Peter is going on vacation and needs to buy various items:

• T-shirt: 199 kr
• Toothbrush set: 58.50 kr
• 3 pairs of underwear: 39 kr per pair

a) What is the total cost?

Total cost = 199 + 58.50 + (3 × 39)
= 199 + 58.50 + 117
= 374.50 kr

b) Peter pays with a 500 kr bill. How much change does he get?

Change = 500 - 374.50 = 125.50 kr

Opgave 2:

Lærke is at a café, and the prices are on a sign:

• Bolle with tun: 37 kr
• Sodavand: 25 kr
• Danskvand: 15 kr
• Cake with a topping: 23 kr
• Coffee with milk: 27 kr

a) What is the price for a Danish bun, a bun with tuna, and a cake?

Cost = Danish bun (15 kr) + bun with tuna (37 kr) + cake (23 kr)
= 15 + 37 + 23 = 75 kr

b) If she orders this same meal 4 times a month for a year (52 weeks), how much will it cost for the year?

Cost per year = 75 kr × 4 × 12 months = 3,600 kr

Opgave 3:

A group of 22 students and 2 teachers are going on a trip to Sæby for 5 days (4 nights). They will stay at a campsite. The expenses per person are:

• Food: 65 kr per day per person
• Cabin rental: 85 kr per night per person
• Transportation: 7,000 kr total
• Other expenses: 125 kr per person
• Additional expenses: 2,500 kr total

a) What is the total cost for the trip?

For 24 people (22 students + 2 teachers):

• Food: $65 \times 5 \times 24 = 7,800$ kr
• Cabin rental: $85 \times 4 \times 24 = 8,160$ kr
• Transport: 7,000 kr
• Other expenses: $125 \times 24 = 3,000$ kr
• Additional expenses: 2,500 kr

Total cost = 7,800 + 8,160 + 7,000 + 3,000 + 2,500 = 28,460 kr

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

Cost per person = 28,460 / 24 = 1,186 kr (rounded)

Opgave 4:

Oliver has an agreement with his parents that if he leaves his confirmation money (25,000 kr) in the bank without using it, they will give him 6% interest per year.

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

Interest for year 1 = $25,000 \times 0.06 = 1,500$ kr
Total after year 1 = 25,000 + 1,500 = 26,500 kr

b) How much will he have after 3 years?

For compound interest:

Year 2: $26,500 \times 1.06 = 28,090$ kr
Year 3: $28,090 \times 1.06 = 29,775.40$ kr

So, Oliver will have 29,775.40 kr after 3 years.

Would you like further clarification on any of these solutions? Here are five related questions you can try:

1. If Peter wanted to buy two toothbrush sets, what would the total cost be in Opgave 1?
2. How much change would Peter get if he only had 400 kr instead of 500 kr in Opgave 1?
3. What would the yearly cost for Lærke be if she ordered the meal 5 times a month instead of 4 in Opgave 2?
4. How would the cost per person change if only 20 students went on the trip in Opgave 3?
5. If Oliver got 8% interest instead of 6%, how much would he have after 3 years in Opgave 4?

Tip: When dealing with interest rates, compound interest grows faster than simple interest!