Given Cost and Price $($demand$)$ functions $C(q)=120q+40000$ and $p(q)=-2\mathrm{.}4q+800,$ what is the marginal revenue when costs are $$90,000?$

The marginal revenue is dollars per item.

If necessary, round to the nearest integer

questoon $2$

Given cost and price $($demand$)$ functions $C(q)=120q+41,100$ and $p(q)=-2q+860,$ what profit can the company earn by selling $40$ items?

It can expect to earn $ in profit.

$($Round answer to nearest dollar.$)$

question $3$

Given cost and price $($demand$)$ functions $C(q)=100q+44,100$ and $p(q)=-1\mathrm{.}9q+860,$ what is the marginal revenue at a production level of $40$ items?

The marginal revenue is dollars per item.

$($Round answer to nearest dollar.$)$