question_answer

The number of terms in the series \[101+99+97+.....+47\] is

A) 25

B) 28

C) 30

D) 20

Correct Answer: B

Solution :

Given series \[101+99+97+.........+47\] So, first term\[a=101\], common difference  \[d=-2\] and last term \[l=47\] We know that last term of a series \[{{T}_{l}}=a+(n-1)d\Rightarrow 47=101+(n-1)(-2)\] \[-54=(n-1)(-2)\Rightarrow n=28\].