2025 MGS(S) PRELIMS P1 Q23

2025 MGS(S) PRELIMS P1 Q23

Secondary 4
4 marks

The first four terms of a sequence are \(T_1=1\times3=3\), \(T_2=1\times3+3\times3=12\), \(T_3=1\times3+3\times3+5\times3=27\), and \(T_4=1\times3+3\times3+5\times3+7\times3=48\).

  1. Find an expression, in terms of \(n\), for \(T_n\).[1]
  2. \(T_p\) and \(T_{p+1}\) are consecutive terms. Find and simplify an expression, in terms of \(p\), for \(T_{p+1}-T_p\).[1]
  3. Explain why two consecutive terms cannot have a difference of 4.[1]
  4. The first three terms of a second sequence are 12, 27 and 48. Using (a) or otherwise, write down an expression, in terms of \(n\), for its \(n\)th term \(S_n\).[1]

Solution:

Solution locked

Sign in to view the step-by-step solution

Similar questions are unavailable for this question.
Answer:(a) \(3n^2\) (b) \(6p+3\) (c) always odd (d) \(3(n+1)^2\)

Need help? Join our JC Math tuition classes.

Learn more