An AP consists of 37 terms. The sum of the three middle most terms is

1.	An AP consists of 37 terms. The sum of the three middle most terms is 225 and thesum of the last three terms is 429. Find the AP.
Answer» Total terms =37first term=a, common difference=d 3 middle terms are 18,19,20th termsa+17d+a+18d+a+19d=2253a+54d=225a+18d=75.....(1) last three terms are 35,36,37th termsa+34d+a+35d+a+36d=4293a+105d=429a+35d=143.....(2) Subtract equation 1 from 2 17d=68d=4a=75-4(35)a=75-140a=-65 AP is -65,-61,-57....

An AP consists of 37 terms. The sum of the three middle most terms is 225 and thesum of the last three terms is 429. Find the AP.

Answer»

Total terms =37first term=a, common difference=d

3 middle terms are 18,19,20th termsa+17d+a+18d+a+19d=2253a+54d=225a+18d=75.....(1)

last three terms are 35,36,37th termsa+34d+a+35d+a+36d=4293a+105d=429a+35d=143.....(2)

Subtract equation 1 from 2

17d=68d=4a=75-4(35)a=75-140a=-65

AP is -65,-61,-57....