Question

Quantity (lamps)	Marginal benefit for Mike	Marginal benefit for Joe	Marginal benefit for Sam
0
1	4	8	5
2	3	6	4
3	2	4	3
4	1	2	2
5	0	0	0

Mike, Joe, and Sam are roommates. They need lamps for their common living room. Lamps in their living room are a public good for these roommates. The marginal benefit that each individual receives from varying numbers of lamps in the living room is given in the table above. The marginal benefit for the second lamp to this group of roommates taken as a whole is

A.17.

B.9.

C.10.

D.13.

Answer 1

Quantity (lamps)	Marginal benefit for Mike	Marginal benefit for Joe	Marginal benefit for Sam	Total Marginal Benefit
0
1	4	8	5	17
2	3	6	4	13
3	2	4	3	9
4	1	2	2	5
5	0	0	0	0

The marginal benefit for the second lamp to this group of roommates taken as a whole is

Answer – D) 13

Marginal benefit for the whole group will be the addition of all individual marginal benefits.

At the second lamp the marginal benefit of Mike is 3, marginal benefit of Joe is 6 and marginal benefit of Sam is 4. The total marginal benefit for the whole group will be 3+6+4 = 13.