P(n)=11+21+…+n1P(2)=11+21>2 Let us assume that P(k)=11+21+…+k1>k is true ∴P(k+1)=11+21+…+k1+k+11>k+1 has to be true. L.H.S. >k+k+11=k+1k(k+1)+1 Since k(k+1)>k(∀k≥0) ∴k+1k(k+1)+1>k+1k+1=k+1 Let P(n)=n(n+1)<n+1 Statement −1 is correct. P(2)=2×3<3 If P(k)=k(k+1)<(k+1) is true Now P(k+1)=(k+1)(k+2)<k+2 has to be true Since (k+1)<k+2 ∴(k+1)(k+2)<(k+2) Hence Statement −2 is not a correct explanation of Statement −1.
Statement - 1: For every natural number n ≥ 2, 1 √1+ 1 √2+…+ 1 √n>√n. Statement -2 : For every natural number n ≥ 2, √n(n+1) < n+1.
JEE Main 2008 — Mathematics Algebra
Statement - 1: For every natural number n≥2,11+21+…+n1>n. Statement −2 : For every natural number n≥2,n(n+1)<n+1.
Held on 30 Apr 2008 · Verified 6 Jul 2026.
Options
- A
Statement −1 is false, Statement −2 is true
- B
Statement −1 is true, Statement −2 is true, Statement −2 is a correct explanation for Statement −1
- C
Statement −1 is true, Statement −2 is true; Statement −2 is not a correct explanation for Statement −1.
- D
Statement −1 is true, Statement −2 is false.
Did you get this right?
Sign in to track your attempts and accuracy.
Your note
Sign in to keep a private note on this question. Nothing you write is ever public.
JEE Main Algebra in other years
More JEE Main Algebra questions
The number of elements in the set $S = \left\{(r, k) : k \in \mathbb{Z} \text{ and } {}^{36}C_{r+1} = \dfrac{6\left({}^{35}C_r\right)}{(k^2 - 3)}\right\}$, is :
Suppose $\mathrm{a}, \mathrm{b}, \mathrm{c}$ are in A.P. and $\mathrm{a}^{2}, 2 \mathrm{~b}^{2}, \mathrm{c}^{2}$ are in G.P. If $\mathrm{a}<\mathrm{b}<\mathrm{c}$ and $\mathrm{a}+\mathrm{b}+\mathrm{c}=1$, then $9\left(\mathrm{a}^{2}+\mathrm{b}^{2}+\mathrm{c}^{2}\right)$ is equal to $\_\_\_\_$ .
Let $S=\left\{z \in \mathbb{C}: 4 z^{2}+\bar{z}=0\right\}$. Then $\sum_{z \in S}|z|^{2}$ is equal to:
Let $S=\{z: 3 \leqslant|2 z-3(1+i)| \leqslant 7\}$ be a set of complex numbers. Then $\min _{z \in S}\left|\left(z+\frac{1}{2}(5+3 i)\right)\right|$ is equal to :
Let $A = \begin{bmatrix} 1 & 0 & 0 \\ 3 & 1 & 0 \\ 9 & 3 & 1 \end{bmatrix}$ and $B = [b_{ij}]$, $1 \leq i, j \leq 3$. If $B = A^{99} - I$, then the value of $\dfrac{b_{31} - b_{21}}{b_{32}}$ is :
Other Mathematics topics for JEE Main
Keep practicing Algebra
Work through every JEE Main Algebra PYQ, year by year.