Answers are
there are four ways to choose the committee
there are three ways to form the committee if person D must be on it
if person B and C must be on the committee, there are two ways to form the committee
Answer:
3) 2.7
Step-by-step explanation:
The distance between two points
and
can be determined by:

Since the points are X(1, 2) and Y(6, 7). The distance between the two points is

the x value for the point located 1/3 the distance from X to Y,

The x value = 
Answer:
A computer costs $225 and a printer $150.
Step-by-step explanation:
Let c be the cost of a computer and p the cost of a printer, then:
3c + p = 825
4c + 2p = 1200
Multiply the first equation by -2:
-6c - 2p = -1650
Add this to the second equation:
-2c = -450
c = 225.
Now substitute c = 225 in the first equation:
3*225 + p = 825
p = 825 - 675 = 150.