math
posted by marie s on .
a political discussion group consists of five Democrats and six Republicans. Four people are selected to attend a conference.
A.in how many ways can four people be selected from this group of eleven?
B.In how many ways can four Republicans be selected from six Republicans?
C.find the probability that the selected group will consist of all Republicans?

the answer is "C"

Thanks, but i need the answer to all three questions

A) choose 4 from 11 which is C(11,4) or 330
b) choose 4 from 6 which is C(6,4) or 15
c) assuming that your group still consists of 4 people
prob = 15/330 = 1/22 
thank you

A. 11 x 10 x 9 x 8/(4 x 3 x 2 x 1) = 330
B. 6!/(4!*2!) = 15
C. (6/11)*(5/10)*(4/9)*(3/8) = 0.04545 
What is the cost of concrete for a walkway that is 15 feet long, 8 feet wide, and 9 inches deep if the concrete costs $30 per cubic yard?

$100