In how many ways can a librarian select 4 novels and 3 plays

In how many ways can a librarian select 4 novels and 3 plays from a collection of 15 novels and 21 plays? What is the second term of (2x^2 - 3y)^9 ? Your answer should be in the form (sign) (numerical factorsXactual powers of variables). A florist has roses, carnations, lilies, and snapdragons in stock. How many different bouquets of 9 flowers can be made? Draw a simple connected graph with 7 vertices and 7 edges with 2 vertices of degree 1, 4 vertices of degree 2, and 1 vertex of degree 4. If you cannot draw such a graph, explain why.

Solution

A. If a librarian selects 4 novels and 3 plays from a collection of 15 novels and 21 plays

then the number of ways that a librarian can select is

=15C4 * 21C3 ways = 15*14*13*12/(4*3*2) * (21*20*19)/(3*2)

= 1365*1330 ways

10. the florists can made the given four flowers types with 9 flowers a bouquet are

Those combinations may have any of the combinations of 9 with same flowers or some with other flowers

It can be made in 9 factorial ways = 9*8*7*6*5*4*3*2 = 31743 ways