3
Answer: CSet 1: Linear Inequalities (Advanced)
Explanation
PROBLEM
A student needs 80 percent average. With 75, 85, 70 on 3 tests, minimum score on 4th test?
A student needs 80 percent average. With 75, 85, 70 on 3 tests, minimum score on 4th test?
A.
80
B.
85
C.✓ Correct
90
D.
95
Detailed Explanation
Choice C is the best answer. (75+85+70+x)/4 >= 80. 230 + x >= 320, x >= 90
Why others are wrong:
A: 80 is incorrect because it does not satisfy the equation.
B: 85 is incorrect because it does not satisfy the equation.
D: 95 is incorrect because it does not satisfy the equation.