(1), (2,3), (4,5,6), (7,8,9,10)................... upto m groupsmth  group contains m terms................like 1st group conyains 1 term....2nd one contains 2 terms..................................................FIND THE SUM OF THE TERMS IN THE 110 th term ?????????  PLS EXPLAIN

Mir Noaman Ali IIT-Roorkee
57 Points
13 years ago

m'th group contains m terms and if u observe ... the last term in the mth group is the sum offrst m natural numbers .... like last term of 1 group is sum of frst natural number =1 last term of 2ndgroup is sum of frst 2 natural numbers =3 .. last term of 3rd group is sum of frst 4 natural numbers =6 .. similarly last term of mth group is sum of frst natural numbers ...... so the last term of 110 th group will be the sum of frst natural numbers .. u have the last term of 110 group.. u have d common difference .. u have number of terms so u can find the frst term .. and now apply sum of n terms in ap formula answer is 665555

iit jee
44 Points
13 years ago

hi,

first group last term =1

second groups last term =1+2

third groups last term=1+2+3

......110 th groups last term =1+2+3+..............+110.

thus you get first and last terms of that group . find the sum .

plzzz approve!!!!!!!

kedar joshi.