Jambmaths question:
Find the sum of the first 11 terms of an A.P. with first term 2 and the common difference 3
Option A:
187
Option B:
157
Option C:
197
Option D:
200
Jamb Maths Solution:
$\begin{align} & a=2,\text{ }d=3\text{, }n=11 \\ & {{S}_{n}}=\tfrac{n}{2}[2a+(n-1)d] \\ & {{S}_{11}}=\tfrac{11}{2}[2\times 2+(11-1)3] \\ & {{S}_{11}}=\tfrac{11}{2}[4+30]=187 \\\end{align}$
Jamb Maths Topic:
Year of Exam: