A=84 B=84 There are solutios in system but not manually please can you solve this question manually ?

4. ABC company uses C transistors every month. For each transistor, each order cost is $A and the annual holding cost is 15 per cent of unit cost. The unit cost depends on the quantity ordered as follows: Quantity Unit Cost ($) 1-99 10 100-299 9.6 300-599 9 600+ 8 > Assume that demand has a constant rate and do not stockout; a) What is the optimal order size? (15p) b) Determine the yearly order quantity. (5p) c) Determine the time between two orders. (5p) A: Refers to the 2*last two digits of your student number. If this value is less than 25, accept A=25. For example, if your student number is 202012512, A is equal to 2*12=24. And this value is less than 25, so A=25 for this question. C: Refers to the 2*last two digits of your student number. If this value is less than 30, accept C=30. For example, if your student number is 202012512, C is equal to 2*12=24. And this value is less than 30, so C=30 for this question. If your student number is 202012524, C is equal to 2*24=48