Question
Question: Let {a<sub>n</sub>} (n ³ 1) be a sequence such that a<sub>1</sub> = 1, and 3a<sub>n+1</sub> – 3a<sub...
Let {an} (n ³ 1) be a sequence such that a1 = 1, and 3an+1 – 3an = 1 for all n ³ 1. Then a2002 is equal to-
A
666
B
667
C
668
D
669
Answer
668
Explanation
Solution
a1 = 1
3an+1 – 3an = 1
an + 1 = =
,
a2 = 31
a3 = a2 + 31 = = 1 + 32
a4 = a3 + 31 = 1+32+31 = 1 + 33
.... .......... ................. .........
.... .......... ................. .........
a2002 = 1 + 32001 = 1 + 667 = 668