Question

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 1

The Correct Option is D

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)