The local botanical society wants to ensure that the gardens in the town park are properly cared for. The group recently spent $100,000 to plant the gardens. The members want to set up a perpetual fund to provide $100,000 for future replantings every 10 years. a) If interest is 5%, how much money is needed for the fund? b) If the last replanting is in year 100, how much is needed for the fund?

The amount of money needed for the fund, if the interest is 5℅ is calculated as follows:

(5% of $100,000) + $100,000

= $5000 + $100,000 = $105,000

(b) In years 100, the interest will be 50% (explained below)

50% of $100,000 is $50,000

If perpetual fund is $100,000,

The amount of money needed for the replanting fund after year 100 is

$100,000 + $50,000 = $150,000

Explanation:

(a) part

After 10 years, the interest is 5%.

5% of 100,000 = (5/100) x 100,000 = $5,000.

The interest will be added to perpetual fund.

Therefore,

The amount needed for the fund after 10 years is

Interest after ten years + perpetual fund = $5,000 + $100,000 = $105,000.

(b) part

If the last replanting is year 100 ago, the percentage interest can be analyzed as follows:

5% in 10years

10% in 20years

15% in 30years

20% in 40years

25% in 50years

30% in 60years

35% in 70years

40% in 80years

45% in 90years

50% in 100years.