M L Aggarwal Solutions for Chapter: Arithmetic Progressions, Exercise 5: Multiple Choice Questions

If the $n^{\mathrm{th}}$ term of an AP is  $2n+1$, then the sum of the first $n$ terms of the AP is 

If the ${18}^{\mathrm{th}}$ and ${11}^{\mathrm{th}}$ terms of an AP are in the ratio $3:2$, then its ${21}^{\mathrm{st}}$ and $5^{\mathrm{th}}$ terms are in the ratio

The number of terms of the AP $3, 7, 11, 15, ......$ to be taken so that the sum is $465$ is

The sum of the first five multiples of $3$ is

The number of two-digit numbers which are divisible by $3$ is

The number of multiples of $4$ that lie between $10$ and $250$ is 

The sum of the first $20$ odd natural numbers is

The sum of first $10$ even whole numbers is