Answer:
d) 330
Step-by-step explanation:
The number of ways can a dance instructor send 4 of her 11 students to summer dance program is C(11 , 4)
That is
ways
by using formula 
now simplification

= 
after cancelling 7! and on simplification
= 
after cancellation we get 330 ways
The number of ways can a dance instructor send 4 of her 11 students to summer dance program is 330
Answer:
I am not 100% about this, but I think that Z=46 Y=30 and X=45
Step-by-step explanation:
First of all, try to understand the questions then try to make a pair of linear equations. After that make the coefficients of x or y equal in both RFD equations by multiplying them by suitable values then add or subtract them ,in such a way which will terminate any one of the variables. Then find the value of left variable. After that just put the value you have found just now In any of the equations and you'll really get the value of the second variable too.