4.06: Arithmetic progression and least sum

0606/21/M/J/26 — Question 3 · 8 marks

In an arithmetic progression, \(u_6=1.5u_3\) and \(S_{10}=255\).
(a)
Find the first term and common difference.
[4]
(b)
Find the least value of \(n\) for which \(S_n>40000\).
[4]