M L Aggarwal Solutions for Exercise 3: Exercise 9.3

Find the sum of the following A.P.

$2,7,12,...$ to $10$ terms

Find the sum given below:

$\left(-5\right)+\left(-8\right)+\left(-11\right)+ ... +\left(-230\right)$

The $4^{\mathrm{th}}$ term of an A.P. is $22$ and ${15}^{\mathrm{th}}$ term is $66$. Find the first term and the common difference. Hence, find the sum of first $8$ terms of the A.P.

If the sum of first $6$ terms of an A.P. is $36$ and that of the first $16$ terms is $256$, find the sum of first $10$ terms.

In an A.P., the sum of its first $n$ terms is $6n-n^2$. Find its ${25}^{\mathrm{th}}$ term.

Find the sum of first $1000$ positive integers.

Find the sum of all natural numbers between $100$ and $200$ which are divisible by $4$.

Find the sum of all natural numbers less than $100$ which are divisible by $6$.