Arithmetic Progressions
RD Sharma
CBSE
Grade 10
Question:
If $a, b, c$ are in A.P., then $\dfrac{a - b}{b - c}$ is equal to:
(a) $1$
(b) $\dfrac{a}{c}$
(c) $\dfrac{b}{c}$
(d) $\dfrac{c}{a}$
Step-by-Step Solution
Key Concept: $b - a = c - b = d \Rightarrow a - b = -d$ and $b - c = -d \Rightarrow \dfrac{-d}{-d} = 1$.
$\dfrac{a - b}{b - c} = \dfrac{-d}{-d} = 1$. [1.0 Mark]
---
🎯 Official CBSE Marking Scheme:
Evaluating ratio $= 1$: 1.0 Mark
Correct Answer: $1$
Confused by the solution? Ask the AI to explain a specific step, tell you where you went wrong, or break down the key trap in this question.