Question

Find the odd one out: \(5,\,10,\,20,\,40,\,100,\,150,\,200\).

• A. \(40\)
• B. \(100\)
• C. \(150\)
• D. \(200\)

Hint:

When finding an odd term, check patterns such as multiplication, addition differences, or powers. The number that breaks the rule is the odd one.

Answer 1

The Correct Option is B

Concept: To find the odd number in a series, we analyze the pattern or rule followed by most numbers in the sequence.

Step 1: Observe the pattern of multiplication. \[ 5 \times 2 = 10 \] \[ 10 \times 2 = 20 \] \[ 20 \times 2 = 40 \] Continuing the same pattern: \[ 40 \times 2 = 80 \] But the given number is \(100\).

Step 2: Identify the mismatch. The expected term should be \(80\), but the series contains \(100\), which breaks the pattern.

Step 3: Verify remaining terms. After \(80\), the pattern could continue as: \[ 80 + 70 = 150 \] \[ 150 + 50 = 200 \] Thus, \(100\) does not follow the consistent pattern. Therefore, the odd number in the series is: \[ \boxed{100} \]