Question 24 of 36intermediate🔧 ApplyNumerical3 marks

Find three prime numbers, all less than 30, whose product is 1955.

Correct Answer

Step 1: Divide 1955 by 5 1955 ÷ 5 = 391

Step 2: Check if 391 is divisible by small primes 391 ÷ 17 = 23

Step 3: Verify 23 is prime 23 is a prime number.

Step 4: Write the prime factorisation 1955 = 5×175 \times 17 × 23

Step 5: Verify all primes are less than 30 All three primes (5, 17, 23) are less than 30.

Answer: The three prime numbers are 5, 17, and 23.

Exercise: Figure it Out (Section 4) | Q: 3 | (Page Page 14)
For More Understanding

Explanation

Find the prime factorisation of 1955. 1955 ÷ 5 = 391. 391 ÷ 17 = 23. 23 is prime. So 1955 = 5×175 \times 17 × 23. All three primes (5, 17, 23) are less than 30.

Solution Steps

  1. Step 1: Divide 1955 by 5: 1955 ÷ 5 = 391

  2. Step 2: Check if 391 is divisible by small primes. 391 ÷ 17 = 23

  3. Step 3: 23 is a prime number.

  4. Step 4: So 1955 = 5×175 \times 17 × 23

  5. Step 5: All three primes (5, 17, 23) are less than 30.

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