If a + 1, 2a + 1, 4a - 1 are in A.P., then the value of a is:
A. 1
B. 2
C. 3
D. 4
Answer: Option B
Solution(By Examveda Team)
Let 1st term = x = a + 1,2nd term = y = 2a + 1 and
3rd term = z = 4a - 1
⇒ y - x = z - y
⇒ 2y = x + z
⇒ 2(2a + 1) = a + 1 + 4a - 1
⇒ 4a + 2 = 5a
⇒ a = 2
Related Questions on Progressions
Find the first term of an AP whose 8th and 12th terms are respectively 39 and 59.
A. 5
B. 6
C. 4
D. 3
E. 7
The sum of the first 16 terms of an AP whose first term and third term are 5 and 15 respectively is
A. 600
B. 765
C. 640
D. 680
E. 690
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