Calculation of Mr. B's Commission:

Mr. B is entitled to receive two types of commission:

1. Commission per unit sold: Mr. B is entitled to receive a commission of 500 per unit sold. This means that for every unit sold, Mr. B will receive a commission of 500.

2. Commission based on gross sales proceeds: Mr. B is entitled to receive a commission based on the gross sales proceeds less total commission thereon exceeding the invoice price. This means that Mr. B will receive a commission on the amount by which the gross sales proceeds less total commission thereon exceed the invoice price. The commission rate for this will be one fourth or 25% of the excess amount.

Example:

Let's assume that Mr. B sold 100 units of a product. The invoice price of each unit is 1000. The total invoice price for 100 units would be 100,000.

The total sales proceeds for 100 units is 150,000. Now, let's calculate the total commission payable to Mr. B.

Commission per unit sold: Mr. B sold 100 units, so he is entitled to receive 500 x 100 = 50,000 as commission for the units sold.

Commission based on gross sales proceeds: The total commission payable to Mr. B based on the gross sales proceeds would be calculated as follows:

Excess amount = Gross sales proceeds - Total commission thereon - Invoice price
Excess amount = 150,000 - 50,000 - 100,000
Excess amount = 0

Since the excess amount is 0, Mr. B is not entitled to receive any commission based on the gross sales proceeds.

Total commission payable to Mr. B: The total commission payable to Mr. B would be the sum of the commission per unit sold and the commission based on gross sales proceeds. In this example, the total commission payable to Mr. B would be 50,000.

Conclusion:

Mr. B is entitled to receive commission per unit sold and commission based on the gross sales proceeds less total commission thereon exceeding the invoice price. The commission rate for the excess amount is one fourth or 25%.

Means to say 1 /4 of selling price + what he get extra of invoice price