# SPM Practice 1 (Arithmetic Progression) : Question 9

Question 9

Show that the volumes of the cylinders in the above diagram form an arithmetic progression and state its common difference.

[Remember - To prove a number sequence is an arithmetic progression:Click here

Step 1: List down any three consecutive terms. Example:${T}_{1},{T}_{2},{T}_{3}$ .]
Step 2: Calculate the values of ${T}_{3}-{T}_{2}$  and ${T}_{2}-{T}_{1}$ .
Step 3: If ${T}_{3}-{T}_{2}={T}_{2}-{T}_{1}$ , then the number sequence is an arithmetic progression]