A salesperson earns a monthly salary of Ksh. 15,000 plus a commission of 5% on sales over Ksh. 100,000. If their total sales for the month were Ksh. 500,000 and tax is 2% of total earnings, calculate

The commission is paid on sales over Ksh 100,000.

$$\text{Eligible sales} = \text{Total sales} - \text{Threshold}$$ $$\text{Eligible sales} = \text{Ksh. } 500,000 - \text{Ksh. } 100,000$$ $$\text{Eligible sales} = \text{Ksh. } 400,000$$

The commission rate is 5% of the eligible sales.

$$\text{Commission} = 5\% \times \text{Ksh. } 400,000$$ $$\text{Commission} = 0.05 \times 400,000$$ $$\text{Commission} = \text{Ksh. } 20,000$$

Total earnings include the monthly salary and the commission.

$$\text{Total earnings} = \text{Monthly salary} + \text{Commission}$$ $$\text{Total earnings} = \text{Ksh. } 15,000 + \text{Ksh. } 20,000$$ $$\text{Total earnings} = \text{Ksh. } 35,000$$

Tax is 2% of his total earnings.

$$\text{Tax} = 2\% \times \text{Total earnings}$$ $$\text{Tax} = 0.02 \times 35,000$$ $$\text{Tax} = \text{Ksh. } 700$$

Net earnings are total earnings minus tax.

$$\text{Net earnings} = \text{Total earnings} - \text{Tax}$$ $$\text{Net earnings} = \text{Ksh. } 35,000 - \text{Ksh. } 700$$ $$\text{Net earnings} = \text{Ksh. } 34,300$$

His monthly net earnings are $\text{Ksh. } 34,300$.