Let c(n, k) = the number of k-membered subsets of an n-membered set. find (a) c(6, k) for k = 0,1, (b) c(7, k) for k = 0,1.

(a) , , , , , , .

(b) , , , , , , , .

Step-by-step explanation:

In this exercise we only need to recall the formula for C(n,k):

where the symbol is the factorial and means

.

By convention 0!=1. The most important property of the factorial is , for example 3!=1*2*3=6.

(a) The explanations to the solutions is just the calculations.

(b) The explanations to the solutions is just the calculations.

For all the calculations just recall that 4! =24 and 5!=120.

the answer is b. 60. each interior angle in 120, so the exterior angle must be 60 in order to add up to 180

step-by-step explanation: