Question

You want to study at the Hogwarts School of Witchcraft and Wizardry after five years. You need 800800800 pieces of muggle-money to study there. You decide to deposit some pieces in the bank at an annual interest rate of 12\%12%12, percent. How many pieces should you deposit today if you want to use the total amount to pay the fees?

Answer 1

Explanation:

I = PRT/100

Where

I represents interest paid on the amount of money deposited.

P represents the principal or amount of money deposited.

R represents interest rate on the deposit.

T represents the duration of the deposit in years.

interest rate is 12%

1 year =12%

5 year =(5*12)%

5 years of interest rate

=60%

P+60% * P=80%

100% * P +60% * P=800

160% * P = 800

160/100 * P = 800

P= 800 * 100/160

= 500

Answer 2

Answer: You should deposit 500 pieces of muggle-money.

Explanation:

We would apply the formula for determining simple interest which is expressed as

I = PRT/100

Where

I represents interest paid on the amount of money deposited.

P represents the principal or amount of money deposited.

R represents interest rate on the deposit.

T represents the duration of the deposit in years.

From the information given,

R = 12%

T = 5 years

Total amount, A = 800

A = P + I

I = A - P

Therefore,

800 - P = (P × 12 × 5)/100

800 - P = 0.6P

800 = 0.6P + P = 1.6P

P = 800/1.6

P = 500