Jitender Gupta and Divya Malik Solutions for Exercise 1: Topic Exercise

Is the following forms an AP? Justify your answer.

$-3, -5, -6, -8,...$

Check that the list of numbers defined by the following ${\mathrm{n}}^{\mathrm{th}}$ term is an AP or not. Also, give the reason.

${\mathrm{t}}_{\mathrm{n}}=3\mathrm{n}+5$

Check that the list of numbers defined by the following ${\mathrm{n}}^{\mathrm{th}}$ term is an AP or not. Also, give the reason.

${\mathrm{t}}_{\mathrm{n}}=9-11{\mathrm{n}}^2$

Check that the list of numbers defined by the following ${\mathrm{n}}^{\mathrm{th}}$ term is an AP or not. Also, give the reason.

${\mathrm{t}}_{\mathrm{n}}=8{\mathrm{n}}^2+\mathrm{n}$

Check that the list of numbers defined by the following ${\mathrm{n}}^{\mathrm{th}}$ term is an AP or not. Also, give the reason.

${\mathrm{t}}_{\mathrm{n}}=4{\mathrm{n}}^3+3$

Show that the sequence defined by ${\mathrm{a}}_{\mathrm{n}}=3{\mathrm{n}}^2-5$ is not an AP.

The $11\mathrm{th}$term of an AP is $80$ and the $16\mathrm{th}$ term is $110$. Find the $31\mathrm{st}$ term.

A sum of $₹5000$ is invested at $8\%$ Simple interest per annum. Calculate the interest at the end of each year. Do these interests from an AP? Find the interest at the end of. $30$ years. Write the answer in rupees.