Answer:
The optimal order size is 654.
Explanation:
As we know that: EOQ = Squareroot (2DS/H)
 where :
S= ordering cost = $25 per order
H = Holding cost per unit = 0.70 per unit
D= Annual demand,sales = 60000/10 = 6000 units
    Solution:
            =  Squareroot ( 2 * 6000 * 25 ) / 0.70
            =  Squareroot (300000/0.70)
             = Squareroot (428571)
       EOQ = 654