Question 792691
Combination=nCr=n!/(n!/((n-r)!r!)
x=.75, y=.25
a)
5C3=10 the coefficient
10x^3y^2 = .26
.
b)
y^5= .00098
.
c) 
5C4=4
5C5=1
4x^4y+x^5=.55
.
d)5*.25=1.25 students
.
Ed