Question

How many '4's are there in the series which comes between two '5's? \[ 3, 4, 4, 5, 4, 5, 4, 2, 1, 4, 5, 4, 5, 7, 4, 5, 4, 5 \]

• A. 4
• B. 5
• C. 6
• D. 3

Hint:

Carefully identify the pairs of '5's and ensure each '4' counted is located strictly between two '5's.

Answer 1

The Correct Option is D

To count the number of '4's that appear between two '5's:
- First pair: \( 5, 4, 5 \) ⇒ 1 '4'
- Second pair: \( 5, 4, 5 \) ⇒ 1 '4'
- Third pair: \( 5, 4, 5 \) ⇒ 1 '4'
Counting all valid '4's, there are 3 '4's that meet the condition.