Home › CBSE Class 11 › mathematics › Linear Inequalities — One Variable, Sign-flip Rule on Negative Multiplication, Solution Sets › A student who scored 70 marks in his first test …
A student who scored 70 marks in his first test of total 100 wants his AVERAGE of two tests to be AT LEAST 75. If x is his second test score (out of 100), the inequality describing x is:
A(70 + x)/2 < 75
B(70 + x)/2 ≥ 75 → x ≥ 80
Cx > 75
Dx = 80
Answer & Solution
Correct answer: B. (70 + x)/2 ≥ 75 → x ≥ 80
Average = (70 + x)/2. 'At least 75' means ≥ 75. So (70 + x)/2 ≥ 75 → 70 + x ≥ 150 → x ≥ 80. He needs 80 or more in the second test.
Related questions
In the inequality 3x + 5 ≤ 2x + 7, after using Rule 1 to move x-terms to one side:Solve the inequality (x - 3)/2 + 1 < 0 over real numbers.In one variable, the inequality 2(x - 1) ≥ x + 5 solves to:Translate: 'The total cost of x kg apples at ₹40/kg and y kg oranges at ₹30/kg should not On a number line, the solution of x ≥ 2 is represented by:Solve 3 ≤ 2x - 1 ≤ 7 (a DOUBLE inequality) for real x.Identify a QUADRATIC inequality (not a linear inequality).Solve -3x + 5 > 2 over real numbers.