Polypropylene cost per jar=0.0495*18.9=R0.93555.
Pigment usage per kg=10/5=2g; usage per g=0.002g; usage per 49.5g jar=0.002*49.5=0.99g.
Pigment cost=0.99*95/1000=R0.09405.
Total cost of one jar (one unit)=R1.0296.
Labour per unit=60/120=0.5hr; labour rate=35/2=R17.5/hr; labour cost per jar=17.5*0.5=R8.75.
Manufacturing cost per jar=1.0296+8.75=R9.7796 (without overheads).
Cost of 15,000 units=15000*9.7796=R146,694.
Time to make 15000 units @ 2 units per hour=7,500 hours.
We don't have any figures for the number of workers (unless the hourly rate of 2 workers implies there are 2 workers). If there are two workers then they each take 7500/2=3,750 hours to make 15,000 units between them. We don't know the length of the working week, but if we assume 37.5 hours, then 15,000 units would take 100 weeks, or approximately 1 year. The overheads are R7500 a month so 12 months=R90,000 per year. Therefore the total annual cost is 146694+90000=R236,694. When this is divided by 15000 we get the cost of each jar including overheads: R15.78 approx.