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

If $P + \frac{1}{Q} = 1$ and $Q + \frac{1}{R} = 1$, then what is PQR?

The correct answer is
-1

Solving for PQR from Algebraic Equations

We are given the following algebraic equations:

  • Equation 1: $P + \frac{1}{Q} = 1$
  • Equation 2: $Q + \frac{1}{R} = 1$

The objective is to determine the value of the product $PQR$.

Deriving Expressions for P and R

From Equation 1, we can isolate $P$:

$P = 1 - \frac{1}{Q}$

Combine the terms on the right side:

$P = \frac{Q - 1}{Q}$

From Equation 2, we can isolate $\frac{1}{R}$:

$\frac{1}{R} = 1 - Q$

Assuming $Q \neq 1$ (which must be true, otherwise $1/R = 0$, which is impossible), we find $R$:

$R = \frac{1}{1 - Q}$

Calculating the Product PQR

Substitute the derived expressions for $P$ and $R$ into the product $PQR$:

$PQR = \left(\frac{Q - 1}{Q}\right) \times Q \times \left(\frac{1}{1 - Q}\right)$

Cancel the variable $Q$ present in the numerator and denominator:

$PQR = (Q - 1) \times \frac{1}{1 - Q}$

Factor out $-1$ from $(Q - 1)$:

$PQR = -(1 - Q) \times \frac{1}{1 - Q}$

Cancel the $(1 - Q)$ terms:

$PQR = -1 \times 1$

$PQR = -1$

Conclusion

The value of $PQR$ calculated from the given equations is -1.

Was this answer helpful?

Important Questions from Algebra (Notes)

  1. What is the remainder when 2023²⁰²⁴ + 2025²⁰²⁴ is divided by 2024?
  2. In an examination, a student scores 4 marks for every correct answer and loses 1 mark for every wrong answer. If she/he attempts all 60 questions and secures 130 marks, the number of questions she/he attempts wrongly, are?

  3. Match List-I with List-II
     

    List-1List-II
    (A) If $\begin{bmatrix}\lambda-1 & 0 \\  0 & \lambda-1 \end{bmatrix} $, then $\lambda$ is(I) 0
    (B) If A=$ \begin{bmatrix}1 & 2 \\2 & 4 \end{bmatrix} $, then $\Delta$ is(II) 1
    (C) If A = $ \begin{bmatrix}1 & 0 \\0 &  \frac{1}{2}  \end{bmatrix} $, then $|A^{-1}|$ is(III) -2
    (D) If $ \begin{bmatrix}a+1 & 1 \\1 & 2 \end{bmatrix} =  \begin{bmatrix}-1 & 1 \\1 & 2 \end{bmatrix} $, then a is(IV) 2

    Choose the correct answer from the options given below:

  4. If (x - 1) is a factor of $2x^2 - 5x + k = 0$, then the value of k is:
  5. If $x = (2+\sqrt{3})^{\frac{1}{3}} + (2+\sqrt{3})^{-\frac{1}{3}}$ and $x^3-3x + k = 0$, then the value of k 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