Express each of the following odd numbers as the sum of 3 prime numbers: a. 29, b. 83, c. 55, d. 53, e. 99

Mathematics
Express each of the following odd numbers as the sum of 3 prime numbers: a. 29, b. 83, c. 55, d. 53, e. 99

ScanSolve AI Answer

Answer

23, 29

Step 1: List the numbers: 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30.

A prime number has no positive divisors other than 1 and itself.

Check each number for divisibility by primes up to its square root.

Step 2: Check 20.
204.47\sqrt{20} \approx 4.47, test primes: 2, 3.
20÷2=1020 \div 2 = 10 (integer). Not prime.

Step 3: Check 21.
214.58\sqrt{21} \approx 4.58, test primes: 2, 3.
Sum of digits: 2+1=32+1=3, divisible by 3.
21÷3=721 \div 3 = 7 (integer). Not prime.

Step 4: Check 22.
224.69\sqrt{22} \approx 4.69, test primes: 2, 3.
22÷2=1122 \div 2 = 11 (integer). Not prime.

Step 5: Check 23.
234.80\sqrt{23} \approx 4.80, test primes: 2, 3.
Odd, not divisible by 2.
Sum of digits: 2+3=52+3=5, not divisible by 3.
Prime.

Step 6: Check 24.
Even and greater than 2.
24÷2=1224 \div 2 = 12 (integer). Not prime.

Step 7: Check 25.
25=5\sqrt{25} = 5, test primes: 2, 3, 5.
Ends in 5.
25÷5=525 \div 5 = 5 (integer). Not prime.

Step 8: Check 26.
Even and greater than 2.
26÷2=1326 \div 2 = 13 (integer). Not prime.

Step 9: Check 27.
275.20\sqrt{27} \approx 5.20, test primes: 2, 3, 5.
Sum of digits: 2+7=92+7=9, divisible by 3.
27÷3=927 \div 3 = 9 (integer). Not prime.

Step 10: Check 28.
Even and greater than 2.
28÷2=1428 \div 2 = 14 (integer). Not prime.

Step 11: Check 29.
295.39\sqrt{29} \approx 5.39, test primes: 2, 3, 5.
Odd, not divisible by 2.
Sum of digits: 2+9=112+9=11, not divisible by 3.
Does not end in 0 or 5, not divisible by 5.
Prime.

Step 12: Check 30.
Even and ends in 0.
30÷2=1530 \div 2 = 15 (integer). Not prime.

The prime numbers are 23 and 29.

23,29\boxed{23, 29}

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Quick Answer

List the numbers: 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30. A prime number has no positive divisors other than 1 and itself.

Express each of the following odd numbers as the sum of 3 prime numbers: a. 29, b. 83, c. 55, d. 53, e. 99
Mathematics

This mathematics problem involves applying core mathematical principles and formulas. Below you will find a complete step-by-step solution with detailed explanations for each step, helping you understand not just the answer but the method behind it.

ScanSolve AI Answer
Step 1: List the numbers: 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30. A prime number has no positive divisors other than 1 and itself. Check each number for divisibility by primes up to its square root. Step 2: Check 20. sqrt(20) ≈ 4.47, test primes: 2, 3. 20 ÷ 2 = 10 (integer). Not prime. Step 3: Check 21. sqrt(21) ≈ 4.58, test primes: 2, 3. Sum of digits: 2+1=3, divisible by 3. 21 ÷ 3 = 7 (integer). Not prime. Step 4: Check 22. sqrt(22) ≈ 4.69, test primes: 2, 3. 22 ÷ 2 = 11 (integer). Not prime. Step 5: Check 23. sqrt(23) ≈ 4.80, test primes: 2, 3. Odd, not divisible by 2. Sum of digits: 2+3=5, not divisible by 3. Prime. Step 6: Check 24. Even and greater than 2. 24 ÷ 2 = 12 (integer). Not prime. Step 7: Check 25. sqrt(25) = 5, test primes: 2, 3, 5. Ends in 5. 25 ÷ 5 = 5 (integer). Not prime. Step 8: Check 26. Even and greater than 2. 26 ÷ 2 = 13 (integer). Not prime. Step 9: Check 27. sqrt(27) ≈ 5.20, test primes: 2, 3, 5. Sum of digits: 2+7=9, divisible by 3. 27 ÷ 3 = 9 (integer). Not prime. Step 10: Check 28. Even and greater than 2. 28 ÷ 2 = 14 (integer). Not prime. Step 11: Check 29. sqrt(29) ≈ 5.39, test primes: 2, 3, 5. Odd, not divisible by 2. Sum of digits: 2+9=11, not divisible by 3. Does not end in 0 or 5, not divisible by 5. Prime. Step 12: Check 30. Even and ends in 0. 30 ÷ 2 = 15 (integer). Not prime. The prime numbers are 23 and 29. 23, 29