Question
Quantitative Aptitude Question on Arithmetic Progression
Let a1 , a2 , a3 , a4 , a5 be a sequence of five consecutive odd numbers. Consider a new sequence of five consecutive even numbers ending with 2a3.
If the sum of the numbers in the new sequence is 450, then a5 is
A
81
B
41
C
61
D
51
Answer
51
Explanation
Solution
The 5 consecutive odd numbers are
a1 , a2 , a3 , a4 , a5
The 5 consecutive even numbers are
2a3 - 8, 2a3 - 6, 2a3 - 4, 2a3 - 2, 2a3
The sum of these 5 numbers = 10a3 - 20 = 450 (given)
∴ a3 = 47 and a5 = 51.
Ans: (51)