What is the prime factorisation of 800?
A(2)(2)(2)(5)(5)(5)
B(2^5)(5^2)
C(2^4)(5^3)
D(2^3)(10^2)
Answer & Solution
Correct answer: B. (2^5)(5^2)
Divide 800 by 2 repeatedly: 800, 400, 200, 100, 50, 25. That gives five 2s (2^5) and 25 = 5^2 left over, so 800 = (2^5)(5^2). Option A has only three 2s. Option C overcounts the 5s. Option D mixes prime and composite bases (10 is not prime).
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