In an examination, 70% of students passed in Physics, 80% students passed in Chemistry, 75% students passed in Mathematics and 85% students passed in Biology and x% students failed in all the four subjects. What is the minimum value of x?
For the next two (02) items that follow:
For the system of linear equations \( 2x + 3y + 5z = 9 \), \( 7x + 3y - 2z = 8 \) and \( 2x + 3y + \lambda z = \mu \).
Under what condition does the above system of equations have infinitely many solutions?
What is the greatest value of the positive integer n satisfying the condition \( 1 + \frac{1}{2} + \frac{1}{4} + \frac{1}{8} + \ldots + \frac{1}{2^{n-1}} < 2 - \frac{1}{1000} \)?
For the next two (02) items that follow:
\( 2x^{2} + 3x - \alpha = 0 \) has roots −2 and \( \beta \) while the equation \( x^{2} - 3mx + 2m^{2} = 0 \) has both roots positive, where \( \alpha > 0 \) and \( \beta > 0 \).