Final answer:
The product of all prime numbers less than 20 is 9,699,690, which is closest to 10^7 (10 million). This can be understood by knowing that the exponent of 10 indicates the number of decimal place shifts needed to reach the full number. So the correct answer is Option C.
Step-by-step explanation:
The product of all prime numbers less than 20 involves the primes: 2, 3, 5, 7, 11, 13, 17, and 19. To determine which power of 10 the product is closest to, we can calculate or estimate this product. Our prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, and their product is 9,699,690, which is closest to 10 million (10^7).
Let's understand the concept of powers of 10. The power (exponent) of 10 is equal to the number of places the decimal is shifted to provide the digit number. For instance, 10 squared (10^2) equals 100, and 10 cubed (10^3) equals 1,000. Therefore, a number like 9,699,690 can be written as 9.69969 × 10^6, which shows that the power of 10 is 6, indicating how many times the decimal point has been shifted to the right to convert it back to the full number.
To compare it to the provided options, the product of the primes is just under 10 million, thus it's closer to 10^7 than to any other provided power of 10. So, the closest answer is (C) 10^7.