#### Principal (initial amount), P = 4,000

#### Annual simple interest rate, R = 2%

#### From date: Oct 12, 2018

#### To date: Nov 12, 2018

#### Duration, T = 31 days

#### Commission fee (withdrawal or payment), F = 1%

#### No. of days in a year, N = 365

## I = Simple interest:

#### I = (P × R × T) ÷ N =

#### (4,000 × 2% × 31) ÷ 365 =

#### (4,000 × 2 × 31) ÷ (365 × 100) =

#### 248,000 ÷ 36,500 ≈

#### 6.794520547945 ≈

#### 6.79

## B = Amount earned before deducting the

commission fee (withdrawal or payment):

#### B = P + I =

#### 4,000 + 6.794520547945 =

#### 4,006.794520547945 ≈

#### 4,006.79

## D = Amount earned after deducting the

commission fee (withdrawal or payment):

#### D = B - F =

#### B - F% × B =

#### (1 - F%) × B =

#### (1 - 1%) × 4,006.794520547945 =

#### 99% × 4,006.794520547945 ≈

#### 3,966.726575342466 ≈

#### 3,966.73

## Pr = Investment profit:

#### Pr = D - P =

#### 3,966.726575342466 - 4,000 =

#### - 33.273424657534 ≈

#### - 33.27