When Unit cost $=30$

EOQ $=$ Sqroot$\{(2*120*20)/(0\mathrm{.}25*30)\}$

$=25\mathrm{.}3$ Units

When Unit cost $=28\mathrm{.}5$

EOQ $=$ sqroot$\{(2*120*20)/(0\mathrm{.}25*28\mathrm{.}5)\}$

$=26$ units

This would be adjusted to $50$ Units

When unit cost $=27$

EOQ $=$ Sqroot$\{(2*120*20)/(0\mathrm{.}25*27)\}$

$=26\mathrm{.}67$ Units

This would be adjusted ro $100$ units

When EOQ $=25\mathrm{.}3$ Units

Total cost $=$ Ordering cost $+$ Holding cost $+$ Product cost

$=(120/25\mathrm{.}3)*20+(25\mathrm{.}3/2)*(0\mathrm{.}25*30)+30*120$

$=$ $$94\mathrm{.}86+$ $$94\mathrm{.}88+$ $$3600$

$=$ $$3789\mathrm{.}74$

When EOQ $=26$ units

$=(120/26)*20+(26/2)*(0\mathrm{.}25*28\mathrm{.}5)+28\mathrm{.}5*120$

$=$ $$92\mathrm{.}31+$ $$92\mathrm{.}63+$ $$3420$

$=$ $$3604\mathrm{.}94$

When EOQ $=26\mathrm{.}67$ Units

$=(120/26\mathrm{.}67)*20+(26\mathrm{.}67/2)*(0\mathrm{.}25*27)+27*120$

$=89\mathrm{.}99+90\mathrm{.}01+3240$

$=$ $$3420$

Order quantity recomended would $100$ units at $$27$ per unit