All Exams Test series for 1 year @ ₹349 only
Question

Consider the following inequalities 

$p^2 - 4q < 4$ 
$3p + 2q < 6$ 

where $p$ and $q$ are positive integers. 

The value of $(p + q)$ is __________

The correct answer is
2

Solving Inequalities for Positive Integers $p$ and $q$

We are given two inequalities with the condition that $p$ and $q$ are positive integers ($p \ge 1$, $q \ge 1$).

  • Inequality 1: $p^2 - 4q < 4$
  • Inequality 2: $3p + 2q < 6$

Analyze Inequality 2 for Integer Solutions

From the second inequality, $3p + 2q < 6$. Since $p$ and $q$ must be positive integers ($p \ge 1, q \ge 1$):

  • If $p = 1$, then $3(1) + 2q < 6 \implies 3 + 2q < 6 \implies 2q < 3$. The only positive integer value for $q$ satisfying this is $q = 1$.
  • If $p = 2$, then $3(2) + 2q < 6 \implies 6 + 2q < 6 \implies 2q < 0$. There are no positive integer values for $q$.
  • If $p \ge 2$, $3p$ will be $6$ or greater, making $3p + 2q < 6$ impossible for positive $q$.

Therefore, the only possible integer pair satisfying $3p + 2q < 6$ with $p \ge 1$ and $q \ge 1$ is $p = 1$ and $q = 1$.

Verify Solution with Inequality 1

Now, we check if the pair $(p=1, q=1)$ satisfies the first inequality, $p^2 - 4q < 4$.

  • Substitute $p=1$ and $q=1$: $(1)^2 - 4(1) < 4$
  • Calculate: $1 - 4 < 4$
  • Result: $-3 < 4$. This is true.

The pair $(p=1, q=1)$ satisfies both inequalities.

Calculate the Value of $p+q$

Using the determined values $p=1$ and $q=1$:

  • $p + q = 1 + 1 = 2$

The value of $(p + q)$ is 2.

Was this answer helpful?

Important Questions from Mathematical Inequalities

  1. A stick of length one meter is broken at two locations at distances of $b_1$ and $b_2$ from the origin (0), as shown in the figure. Note that $0 < b_1 < b_2< 1$. Which one of the following is NOT a necessary condition for forming a triangle using the three pieces?
    Note: All lengths are in meter. The figure shown is representative.

  2. Consider the following inequalities.
    (i) $3p - q < 4$ 
    (ii) $3q - p < 12$ 
    Which one of the following expressions below satisfies the above two inequalities?

  3. Consider the following inequalities. 
    (i) $2x - 1 > 7$ 
    (ii) $2x - 9 < 1$ 
    Which one of the following expressions below satisfies the above two inequalities?

  4. Which one of the following is a representation (not to scale and in bold) of all values of $x$ satisfying the inequality  $2 – 5x \le \frac{6x-5}{3}$on the real numberline?

  5. The range of values of x satisfying the inequality $x^2 -3x+2 < 0$ is
Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App