Math Problem Statement

A set of math problems related to prime factorization, multiples, sums, and factors extracted from an uploaded image.

Solution

Here’s the solution for each of the questions visible in the uploaded image:


Question 1:

The prime factorization of 2100 is:

Break down 2100:
2100=2×2×3×5×5×72100 = 2 \times 2 \times 3 \times 5 \times 5 \times 7

Answer: (c) 2×2×3×5×5×72 \times 2 \times 3 \times 5 \times 5 \times 7


Question 2:

The smallest 4-digit number when expressed as a product of primes is:

The smallest 4-digit number is 1000. Its prime factorization:
1000=2×2×2×5×5×51000 = 2 \times 2 \times 2 \times 5 \times 5 \times 5

Answer: (a) 2×2×2×5×5×52 \times 2 \times 2 \times 5 \times 5 \times 5


Question 3:

The prime factorization of 640 is:

Break down 640 into prime factors:
640=2×2×2×2×2×2×2×2×2×2=210.640 = 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 = 2^{10}.

Answer: (a) 2×2×2×2×2×2×2×2×2×22 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2


Question 4:

A common multiple of both 9 and 7 is A. This number is between 1200 and 1300.

The least common multiple (LCM) of 99 and 77 is: LCM(9,7)=63\text{LCM}(9, 7) = 63 Now, find multiples of 63 between 1200 and 1300: 63×19=1197(too small),63×20=1260(fits range).63 \times 19 = 1197 \quad (\text{too small}), \quad 63 \times 20 = 1260 \quad (\text{fits range}).

Answer: (c) 1260


Question 5:

The sum of the first four multiples of 6 is:

The first four multiples of 66 are:
6,12,18,246, 12, 18, 24
Sum: 6+12+18+24=606 + 12 + 18 + 24 = 60

Answer: (a) 66


Question 6:

The sum of the first five multiples of 6 is:

The first five multiples of 66 are:
6,12,18,24,306, 12, 18, 24, 30
Sum: 6+12+18+24+30=906 + 12 + 18 + 24 + 30 = 90

Answer: (a) 90


Question 7:

The difference between the tens digit and the units digit of the sum of the first five multiples of 6 is:

From Question 6, the sum of the first five multiples of 66 is: 9090
The tens digit is 99, and the units digit is 00. Difference: 90=99 - 0 = 9

Answer: (d) 9


Question 8:

Which of the following is NOT a factor of 316?

The prime factorization of 316316 is: 316=2×2×79316 = 2 \times 2 \times 79
The factors are: 1,2,4,79,158,3161, 2, 4, 79, 158, 316
Among the options, 88 is NOT a factor.

Answer: (b) 8


Question 9:

What is the prime factorization of 37800?

Break down 3780037800:
37800=2×2×3×3×3×5×5×737800 = 2 \times 2 \times 3 \times 3 \times 3 \times 5 \times 5 \times 7

Answer: (c) 2×2×3×3×3×5×5×72 \times 2 \times 3 \times 3 \times 3 \times 5 \times 5 \times 7


Question 10:

Factors of 30 are:

The factors of 3030 are: 1,2,3,5,6,10,15,301, 2, 3, 5, 6, 10, 15, 30

Answer: (b) 1,2,3,5,6,10,15,301, 2, 3, 5, 6, 10, 15, 30


Would you like detailed explanations for any of these, or should I proceed to additional problems? Let me know!


Related Questions:

  1. How do you find the least common multiple (LCM) of two numbers?
  2. What is the difference between factors and multiples?
  3. How can you verify the prime factorization of a number?
  4. Why is prime factorization useful in solving problems?
  5. How do you find the sum of consecutive multiples efficiently?

Tip:

To quickly calculate sums of consecutive multiples, use the formula for the sum of an arithmetic sequence: S=n2×(first term+last term),S = \frac{n}{2} \times (\text{first term} + \text{last term}), where nn is the number of terms.

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Math Problem Analysis

Mathematical Concepts

Prime Factorization
Multiples
Factors
LCM (Least Common Multiple)
Arithmetic Sequences

Formulas

Prime Factorization: Breaking a number into prime factors
Sum of Arithmetic Sequence: S = n/2 × (first term + last term)
LCM Calculation

Theorems

Properties of Prime Numbers
Factorization Techniques
Rules for Finding LCM and GCD

Suitable Grade Level

Grades 6-8