Question

The first term in a sequence is 1 and the second term is 5. From the third term on each term is the average (arithmetic mean) of all preceding terms. What is the 25th term in the sequence?

• A. $2$
• B. $3$
• C. $5$
• D. $2.5$

Answer 1

The correct option is B $3$

Start constructing the sequence until you see the pattern
1...5...(average of 1 and 5 = 3)...(average of 1, 5, and 3 = 3)...(average of 1,5,3 and 3 = 3)
now you can see that all subsequent terms will be 3