Math Problem Statement

Find the number of zeros in the product of (60^8 × 90^12 × 25^15).

Solution

To find the number of zeros in the product of (608×9012×2515)(60^8 \times 90^{12} \times 25^{15}), we need to determine how many factors of 10 are present in this product. A factor of 10 is created by multiplying a factor of 2 and a factor of 5. Therefore, we need to count the number of factors of 2 and 5 in the prime factorizations of 60860^8, 901290^{12}, and 251525^{15}.

Step 1: Prime Factorization of Each Number

  1. 60:
    60=22×3×560 = 2^2 \times 3 \times 5
    Therefore, 608=(22×3×5)8=216×38×5860^8 = (2^2 \times 3 \times 5)^8 = 2^{16} \times 3^8 \times 5^8.

  2. 90:
    90=2×32×590 = 2 \times 3^2 \times 5
    Therefore, 9012=(2×32×5)12=212×324×51290^{12} = (2 \times 3^2 \times 5)^{12} = 2^{12} \times 3^{24} \times 5^{12}.

  3. 25:
    25=5225 = 5^2
    Therefore, 2515=(52)15=53025^{15} = (5^2)^{15} = 5^{30}.

Step 2: Combine All Factors Multiplying all the factorizations together: 608×9012×2515=(216×38×58)×(212×324×512)×(530)60^8 \times 90^{12} \times 25^{15} = (2^{16} \times 3^8 \times 5^8) \times (2^{12} \times 3^{24} \times 5^{12}) \times (5^{30})

Combine like terms: =216+12×38+24×58+12+30= 2^{16 + 12} \times 3^{8 + 24} \times 5^{8 + 12 + 30} =228×332×550= 2^{28} \times 3^{32} \times 5^{50}

Step 3: Determine Number of Zeros The number of zeros is determined by the limiting factor between the counts of 2s and 5s. Since a zero is formed by a factor of 10=2×510 = 2 \times 5, the limiting factor is the smaller of the counts of 2s and 5s.

Here, we have:

  • Factors of 2: 28
  • Factors of 5: 50

Since factors of 2 are the limiting factor, the number of zeros is min(28,50)=28\min(28, 50) = 28.

Answer: The product has 28 zeros.

Would you like more details or have any questions?

Here are some related questions you might find useful:

  1. How do you find the number of trailing zeros in a factorial?
  2. What is the prime factorization method, and how is it used in number theory?
  3. How does multiplying large powers affect the number of trailing zeros in a product?
  4. How do the powers of other primes affect the number of trailing zeros?
  5. How would the number of zeros change if additional factors were introduced?

Tip: When finding the number of trailing zeros in a product, always look for pairs of 2s and 5s, as each pair forms a factor of 10, contributing to a trailing zero.

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Math Problem Analysis

Mathematical Concepts

Prime Factorization
Powers and Exponents
Counting Factors

Formulas

n = 2^a × 3^b × 5^c, where n is the number, and a, b, c are the powers of the prime factors

Theorems

Factor of 10 is created by multiplying a factor of 2 and a factor of 5

Suitable Grade Level

High School