Prime factors of 143 are(a). 2,11,13(b). 11,13(c). 2,3,7(d). None

To find the prime factors of 143, we follow these steps:

Start by checking if 143 is divisible by the smallest prime numbers: 2, 3, 5, 7, 11, and so on.

Check divisibility by 2: 143 is an odd number, so it is not divisible by 2.

Check divisibility by 3: The sum of the digits of 143 is 1 + 4 + 3 = 8. Since 8 is not divisible by 3, 143 is not divisible by 3.

Check divisibility by 5: 143 does not end in 0 or 5, so it is not divisible by 5.

Check divisibility by 7: 143 ÷ 7 = 20.428, which is not an integer. Therefore, 143 is not divisible by 7.

Check divisibility by 11: 143 ÷ 11 = 13, which is an integer.

So, 143 = 11 × 13.

Both 11 and 13 are prime numbers.

Thus, the prime factors of 143 are 11 and 13.

The correct answer is (b). 11, 13.