In this nexylexy question, i need to calculate additional cash$-$outflow required for each additional unit produced $,$ do I add the cost of the interest for the new production machine and the discount for the proposed marketing increase of sales

If i add $20\%$ of sales to R$210600000=$ R$42120000/$ R$585=72000($ i get $72000$ extra units that Nexylexy must produce.

They also say the inventory levels must be increased with $15\%,$ do I work on the $15\%$ on $360000$ units or do I work out the $20\%$ on the sales value.

Depreciation is not a cash outflow, but interest paid and disc is a cash outflow.

Can I just get clarity on this?

Celeste