2.1 Under the employment promotion programme, ink-pens can be sold at the educational institutions and commercial offices during break-hour. A vendor can purchase the ink-pens at a discounted rate of R5 per unit against the selling price of R8. The vendor has estimated the following probability distributions for the number of pens demanded. Number of pens 150 160 170 180 190 200 Probability 0.04 0.19 0.33 0.26 0.11 0.07 How many ink-pens should be ordered to maximise the vendor’s expected profit?