====== Question 1 Review Exercise 5 ====== Solutions of Question 1 of Review Exercise 5 of Unit 05: Vectors. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan. ===== Question 1 ===== Chose the correct option. i. If $t_n=6 n+5$ then $t_{n+1}=$ * %%(a)%% $6 n-1$ * (b) $6 n+11$ * %%(c)%% $6 n+6$ * (d) $6 n-5$ \\ See Answer(b): $6 n+11$ ii. The sum to infinity of the series: $1+\dfrac{2}{3}+\dfrac{6}{3^2}+\dfrac{10}{3^3}+\dfrac{14}{3^4}+\ldots$ * %%(a)%% $6$ * (b) $2$ * %%(c)%% $3$ * (d) $4$ \\ See Answer(c): $3$ iii. Sum the series:$1+2.2+3.2^2+\cdots+100.2^{\prime \prime}$ * (a) $99.2^{100}$ * (b) $100.2^{100}$ * %%(c)%% $99.2^{100}+1$ * %%(d)%% $1000.2^{100}$ \\ See Answer(c): $99.2^{100}+1$ iv. The $n^{t h}$ term of the series: $1.2+2.3+3.4+\ldots$ * (a) $n^2-n$ * %%(b)%% $n^2+n$ * %%(c)%% $n^2$ * (d) None of these \\ See Answer(b): $n^2+n$ v. Sum of $n$ terms of the series whose $n^{t h}$ term is $1+2^n$ * (a) $n \cdot 2^{n-1}$ * %%(b)%% $(n+1)+2^{n+1}$ * %%(c)%% $n+2(2^n-1)$ * (d) None of these \\ See Answer(c): $n+2(2^n-1)$ vi. Evaluate $\Sigma\left(3+2^r\right)$, where $r=1,2,3, \ldots, 10$ * %%(a)%% $2051$ * (b) $2049$ * %%(c)%% $2076$ * (d) $1052$ \\ See Answer(c): $2076$ vii. What is the $n$ term of the series: $1+\dfrac{1+2}{2}+\dfrac{1+2+3}{3}+\ldots$ * %%(a)%% $\dfrac{n+1}{2}$ * (b) $\dfrac{n(n+1)}{2}$ * %%(c)%% $n^2-(n+1)$ * (d) $\dfrac{(n+1)(2 n+3)}{2}$ \\ See Answer(a): $\dfrac{n+1}{2}$ viii. Sum of $n$ terms of the series $1^3+3^3+5^3+7^3+\ldots$ * (a) $n^2(2 n^2-1)$ * (b) $2 n^3+3 n^2$ * %%(c)%% $n^3(n-1)$ * (d) $n^3+8 n+4$ \\ See Answer(a): $n^2(2 n^2-1)$ ====Go To==== [[math-11-kpk:sol:unit05:Re-ex5-p2|Question 2 & 3 >]]