The Umueri Community condemned an inner-city housing area and replaced it with a modern development. The project involves demolishing and building. The following is a summary of the situation.

1. 300 substandard houses can be demolished. Each house occupies a .25-acre lot. The cost of demolishing a condemned house is N2000.
2. Lot sizes for new single-, double-, triple-, and quadruple-family homes (units) are .18, .28, .4, and .5 acre, respectively. Streets, open space, and utility easements account for 15% of available acreage.
3. In the new development, the triple and quadruple units account for at least 25% of the total. Single units must be at least 20% of all units, and double units at least 10%.
4. The tax levied per unit for single, double, triple, and quadruple units is N1000, N1900, N2700, and N3400, respectively.
5. The construction cost per unit for single-, double-, triple-, and quadruple-family homes is N50,000, N70,000, N130,000, and N160,000, respectively.
6. Financing through a local bank is limited to N15 million.

How many units of each type should be constructed to maximize tax collection?