Question

If a monopolist wants to increase the quantity sold from 5 5 units to 6 6 ​units, it cuts the price from $ 16 $16 to $ 14 $14. The marginal revenue​ = ​$ nothing . ​(Enter your response as a whole​ number.)

Answer 1

If a monopolist wants to increase the quantity sold from 5 units to 6 ​units and  it cuts the price from $ 16 to $ 14

total revenue of 5 th unit=P*Q=5*16=80

TR(6)=6*14=84

MR(n)=(TR(n)-TR(p))/(n-p)
MR(n)= MR of n th unit of output
TR(n)=TR of n units of output
TR(p)=TR of p units of output
it is true for n>p

MR(6)=(84-80)/(6-5)=4

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if the question is

If a monopolist wants to increase the quantity sold from 5 5 units to 6 6 ​units, it cuts the price from $ 16 to $ 14

TR(55)=55*16=880

TR(66)=66*14=924

MR(66)=(924-880)/(66-55)=4

the MR is $4, it is same for both problems  in thsi case but it is just a coinciance