Marisa needs to hire at least 10 staff members for an upcoming project. The staff members will be made up of junior directors, who will be paid $640 per week, and senior directors, who will be paid $880 per week. Her budget for paying the staff members is no more than $9,700 per week. She must hire at least 3 junior directors and at least 1 senior director. Which of the following systems of inequalities represents the conditions described if x is the number of junior directors and y is the number of senior directors?

The correct answer is: 640x + 880y ≤ 9,700
x + y  ≥ 10
x ≥ 3 , y ≥ 1

HINT -  Let number of junior directors = x and number of senior directors = y  and then form linear equations in two variable
SOLUTION – Let number of junior directors = x
Number of senior directors = y
According to question, Marisa hires at least 10 staff members
i.e. Total number of junior and senior directors ≥  10
x + y ≥ 10.                      ---- (1)
Further, it is given that
Income given to junior directors = $ 640 per week
Income given to senior directors = $ 880 per week
Budget for paying all staff members ≤ $ 9700
i.e.  640x + 880y ≤ 9700.      ---- (2)
Now, Number of junior directors ≥ 3
x ≥ 3.           ---- (3)
And number of senior directors hired ≥ 1
 y ≥ 1            ---- (4)
Observing (1) , (2) , (3) and (4)
We get option B is correct answer.