The 4th term of an A.P. is 22 and 15th term is 66. Find the first term and the common difference. Hence, find the sum of first 8 terms of the A.P.
Answers
Answered by
60
Given :-
- 4th term of AP = 22
- 15th term of AP = 66
To Find :-
- 8th term of AP
Therefore :-
From 1st and 2nd equation :-
- we get
➡a - 14d = 66 [ equation 1 ]
➡a + 3 d = 22 [equation 2]
- 11 d = 44
- d = 4
Put d = 4 in equation 1
- a + 3(4)=22
- a = 22- 12
- a = 10
Now :-
Final answer is 192 .
Similar questions