#### Principal (initial amount), P = 19,290

#### Due interest, I = 300

#### Annual simple interest rate, R = 2.85%

#### Commission fee (withdrawal or payment), F = 0.2%

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

## T = The investment duration period, in days:

#### T = (N × I) ÷ (P × R) =

#### (365 × 300) ÷ (19,290 × 2.85%) =

#### (365 × 300) ÷ (19,290 × ^{2.85}/_{100}) =

#### (100 × 365 × 300) ÷ (19,290 × 2.85) =

#### 10,950,000 ÷ 54,976.5 =

#### 199.176011568579 ≈

#### 199.18

#### T = 200 days

## B = Amount earned before deducting the

commission fee (withdrawal or payment):

#### B = P + I =

#### 19,290 + 300 =

#### 19,590

## D = Amount earned after deducting the

commission fee (withdrawal or payment):

#### D = B - F =

#### B - F% × B =

#### (1 - F%) × B =

#### (1 - 0.2%) × 19,590 =

#### 99.8% × 19,590 =

#### 19,550.82

## Pr = Investment profit:

#### Pr = D - P =

#### 19,550.82 - 19,290 =

#### 260.82