Using the quantity discount model

Annual Demand$=200,000$

The order cost$=$ $$100$

Annual holding rate$=25\%$

Price varies depending on the order quantity per the following schedule:

Orders between $1$ to $50000$ units cost $$11$

Orders of $50,001$ to $150,000$ cost $$10\mathrm{.}75$

Order greater than $150,000$ cost $$10\mathrm{.}50$

Determine the optimal order quantity using the price discount model discussed in class. Show all you work.

$1.$ CALCULATE THE EOQ at a cost of $$10\mathrm{.}50.$ Round order quantities to the nearest whole number

$2.$ Is the EOQ you calculated at a cost of $$10\mathrm{.}50$ considered feasible? YES$/$NO

$3.$ CALCULATE THE EOQ at a cost of $$10\mathrm{.}75.$ Round order quantities to the nearest whole number

$4.$ Is the EOQ you calculated at a cost of $$10\mathrm{.}75$ considered feasible? YES$/$NO

$5.$ CALCULATE THE EOQ at a cost of $$11.$ Round order quantities to the nearest whole number

$6.$ Is the EOQ you calculated at a cost of $$11$ considered feasible? YES$/$NO

I know from doing a first attempt the question one$$s answer is $3904,$ question $2$ is no$,$ question $4$ is no$,$ and question $6$ is yes!!! I need $3$ and $5?$