If the sum of the series 2 + 5 + 8 + 11...... | vedclass

Name: PDF Generator App | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(b) Series, $2 + 5 + 8 + 11............$

$a=2,d=3$ and let number of terms is $n$

then sum of $A.P.$ ${a_1} + {a_5} + {a_{10}} + {a_{15}} + {a_{

Vedclass · Accepted Answer

$200$

Vedclass · Answer

(b) Series, $2 + 5 + 8 + 11............$

$a=2,d=3$ and let number of terms is $n$

then sum of $A.P.$ ${a_1} + {a_5} + {a_{10}} + {a_{15}} + {a_{20}} + {a_{24}} = 225$

$ \Rightarrow $ $60100 = \frac{n}{2}\left\{ {2 	imes 2 + (n - 1)3} ight\}$

$ \Rightarrow $ $120200 = n(3n + 1)$

$ \Rightarrow $ $3{n^2} + n - 120200 = 0$

$ \Rightarrow $ $(n - 200)(3n + 601) = 0$

Hence $n = 200$.

If the sum of the series $2 + 5 + 8 + 11............$ is $60100$, then the number of terms are

Similar Questions

If three positive numbers $a, b$ and $c$ are in $A.P.$ such that $abc\, = 8$, then the minimum possible value of $b$ is

The sum of first $n$ natural numbers is

In an $\mathrm{A.P.}$ if $m^{\text {th }}$ term is $n$ and the $n^{\text {th }}$ term is $m,$ where $m \neq n$, find the ${p^{th}}$ term.

If $\frac{1}{{p + q}},\;\frac{1}{{r + p}},\;\frac{1}{{q + r}}$ are in $A.P.$, then

If the sum of $n$ terms of an $A.P.$ is $nA + {n^2}B$, where $A,B$ are constants, then its common difference will be