Answer:
not choosing all mysteries
Step-by-step explanation:
The complement of an event is the remaining possibilities.
Our event is Mariah choosing 3 mysteries.
The other possibilities include that she chooses at least one book that is not a mystery; this means the complement is not choosing all mysteries.
Carpet Master would be cheaper because 6 x 9 would be 54 $$$
Answer:

Step-by-step explanation:
1) if to re-write the given equation into slope-interception form, then:

the slope of the given line is 5/2;
2) according to the rule of perpendicular, the required slope should be:
s*(5/2)=-1;
3) if to solve this equation (s*5/2=-1), then s=-2/5 or -0.4.
90,400-7,100=83,300
83,300/12=6,941.66667
Monthly Salary Rounded: 6,941.67