yasirnasir wrote:Hi All,
Can someone explain the quickest and clearest way to solve this diagnostic test question?
The product of all the prime numbers less than 20 is
closest to which of the following powers of 10 ?
(A) $$^{10^9}$$
(B) $$^{10^8}$$
(C) $$^{10^7}$$
(D) $$^{10^6}$$
(E) $$^{10^5}$$
Since the answer choices are VERY spread out, we can BALLPARK.
For every value that we round UP, we should compensate by rounding another value DOWN.
2*3*5*7*
11*13*
17*19
210 *
10*15 *
15*20
200*
150*
300 = 9,000,000.
The closest power of 10 = 10,000,000 = 10�.
The correct answer is
C.
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