Questions

Calculate the sum of the series of natural numbers: $\rm 1 + 3 + 5 + 7 + \dots $ to $20$ terms.

Calculate the sum of the series of natural numbers: $\rm 1 + 2 + 3 + 4 + \dots $ to $15$ terms.

Calculate the sum of the series of natural numbers: $\rm 1 + 2 + 3 + 4 + \dots $ to $20$ terms.

Find the sum of the series: $\rm 1+\frac{1}{4}-\frac{2}{4}-\frac{5}{4} - \dots $to $10$ terms.

Find the sum of the series : $\rm - 3 + 1 + 5 + \dots $ to $\rm 50$ terms.

Find the sum of the series $\rm 12+9+6+\dots$ to $32$ terms

Find the sum of the series $\rm 5 + 11 + 17 + \dots $ to 20 terms.

Sharmila started to work in 2075 BS at an annual salary of Rs 2,50,000 and received a Rs 10,000 rise every year. 

1. Which sequence is related to given situation?
2. In what year would her annual salary reach Rs 3,50,000?
3. Find the monthly salary of Sharmila on $\rm 8^{th}$ years.
4. Fnd the means between 2,50,000 and Rs 3,00,000..

In a flower bed there are 23 rose plants in the first row, 21 in the second row and 19 in the third row and so on. There are 5 plants in the last row.

1. Is this sequence are in arithmetic progression?
2. How many flower beds are there? 
3. How many plants are there in $\rm 6^{th}$ row? 
4. Find the arithmetic means between 23 and 5.

Divide 24 into three parts, which are in arithmetic sequence, such that their product is 224.