Question

Choose the number pair which is different from others-

• A. 181-48
• B. 170-55
• C. 131-42
• D. 80-25

Hint:

Check the properties of resulting numbers (like prime or composite) to identify the odd pair in number series.

Answer 1

The Correct Option is C

Analyze the pairs by subtracting the second number from the first:
181 - 48 = 133
170 - 55 = 115
131 - 42 = 89
80 - 25 = 55
Observe the results:
133, 115, and 55 are all composite numbers (not prime), but 89 is a prime number.
Hence, the pair 131-42 is different because the difference 89 is prime, whereas the others are not.