R K Bansal Solutions for Exercise 1: EXERCISE

Find the sum of first $51$terms of an A.P. whose $2^{\text{nd }}$ and $3^{\text{rd }}$ terms are $14$and $18$respectively.

The sum of first 7 terms of an A.P. is $49$and that of first 17 terms of it is $289 .$ Find the sum of first $\mathrm{n}$ terms.

The first term of an A.P. is$5,$ the last term is $45$and the sum of its terms is $1000 .$ Find the number of terms and the common difference of the A.P.

Find the sum of all natural numbers between $250$and $1000$which are divisible by $9$

The first and the last terms of an A.P. are $34$and $700$respectively. If the common difference is $18,$ how many terms are there and what is their sum ?

In an A.P., the first term is $25,{\mathrm{n}}^{\mathrm{th}}$ term is -$17$and the sum of $\mathrm{n}$ terms is $132$. Find $\mathrm{n}$ and the common difference.

If the $8^{\text{th }}$ term of an A.P. is $37$and the ${15}^{\text{th }}$ term is $15$more than the ${12}^{\text{th }}$ term, find the A.P. Also, find the sum of first $20$terms of this  A.P.

Find the sum of all multiples of $7$lying between $300$and $700.$