Find the sum: `25+28+31+\ dot\ +100` (ii) `18+15 1/2+13+\ dot+\ (-49 1/2)`

Find the sum: 25+ 28+31+…+100.

Find the sum: 25+28+31+.+100 (ii) 18+15(1)/(2)+13++(-49(1)/(2))

How many terms are there in the A.P? 7,\ 10 ,\ 13 ,\ 43. (ii) -1,\ -5/6,\ -2/3,\ -1/2,\ ddot,(10)/3dot (iii) 7,\ 13 ,\ 19 ,\ ddot,\ 205 . (iv) 18 ,\ 15 1/2,\ 13 ,\ ddot,\ -47 .

Find the number of terms in each of the following APs : (i) 7, 13, 19, . . . , 205 (ii) 18 ,\ 15 1/2,\ 13 ,\ dot\ dot\ dot\ ,\ - 47

Find the sum 1+4+13+40+121+dot

Find the sum 1+4+13+40+121+dot

Find the sum: i] 28 + 31 + ·········· + 100 ii] 28 + 26 + ·········· + 10 . iii] 3 + 11 + 19 + ......+ +803 .

How many terms are there in the A.P? 7, 10 , 13 , 43. (ii) -1, -5/6, -2/3, -1/2, ddot,(10)/3dot (iii) 7, 13 , 19 , ddot, 205 . (iv) 18 , 15 1/2, 13 , ddot, -47 .

Find the number of terms in each of the following APs : (i) 7, 13, 19, . . . , 205 (ii) 18 ," "15 1/2," "13 ," "dot" "dot" "dot" "," " 47

Find the sum of n terms \ of the series: 1/(1. 2)+1/(2. 3)+1/(3. 4)+dot+ 1/n dot((n+1))