Find the sum upto the nth term of the series (1+3)+(5 + 7 +9+11)+(13 + 15 + 17 + 19 + 21+23)

The sum of 100 terms of the series 1 +3 + 5 +7 + 9 +11 + 13 +15 + ….. is :

The nth term of the series 3+7+13+21+... is

The nth term of the series 3+7+13+ 21+….... is

Find out the next term in the series 7,11,13,17,19, -" ?

Find the sum of 23 terms of the AP 5,9,13,17,……

Without adding, find the sum: 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 + 21 + 23

Find the sum upto nth term : ,1 + 4 + 13 .+ 40 + ........

Without adding, find the sum: 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19+ 21 + 23

Find the sum to n terms of the series (1)/(1*3*5*7*9)+(1)/(3*5*7*9*11)+(1)/(5*7*9*11*13)+"......" . Also, find the sum to infinty terms.